Open Maps

Coastal erosion

2012-01-31T19:12:00.001Z

I've seen a report that shows the total erosion along parts of the East Yorkshire coast. The coast is one of the fastest eroding coastlines in Europe. The average rate of loss is about 2.5 metres each year, but last year there were unusually large losses in a few areas. South of Withernsea the cliff receded by ten metres. Near Waxholme seven metres disappeared.

Holderness is a rich agricultural plain east of Hull. The clay it is made of was deposited as the last glaciers melted about 10,000 years ago. As the sea level rose again separating England from modern-day Netherlands and Denmark the soft clay became the new coastline. The cliffs range from a metre to tens of metres high, but the action of the sea easily undercuts the cliff and then causes collapse. The very dry year last year may have contributed because the clay shrinks as it dries out, leaving fissures that make collapses easier. Most of the coast is not, now, defended so these loses will continue, but probably at the average rate overall.

Left to itself, in about 10,000 more years, the plain would probably erode back to the old coastline which was a limestone line marking the edge of the Yorkshire Wolds from Flamborough Head to Hessle on the bank of the Humber.

All this erosion makes keeping the OSM coastline up to date is hard work.

Homogenised data? No thanks

2012-01-22T19:59:00.000Z

I follow the changes made in the East Yorkshire area. Andy Ayre created a twitter feed for the area which generates tweets as osmeastriding. AndrewArm creates an RSS feed for the area too. Then there is the ITOWorld tool which is helps me look at the editors for a selected area.

Andy Ayre's twitter feed is based on a rectangle that encloses the county, so it also includes York, part of North Yorkshire and part of northern Lincolnshire too. It is very quick so edits appear only a few minutes after they were made and I check it every day. Andy's algorithm looks for changesets that fall within the rectangle, so big changesets that span the county are ignored whether objects in the county are edited or not.

AndrewArm's RSS feed is based on the polygon that describes the county and so it is more focussed. It is up to a day behind the edit. It does, however, show any edits in the county, including changesets that cover bigger areas than the county, so-called big edits.

ITOWorld's system will be familiar to many. It allows you to choose a rectangle to monitor and provides an RSS feed for changes in the selected area. This is a day or two behind the edits and the size of rectangle is limited and is much smaller than the size of East Yorkshire.

Monitoring an area reveals new mappers. Once they have made a few edits I usually send them a message saying 'Hi' and offering info or help. Newbies often want to check something or ask how to do something.

Monitoring also shows up vandalism. Speedy action means vandalism can be reverted without much risk. Reverting a vandal's edit means he may be dissuaded from doing it again, but at least the harm is limited.

Another thing that monitoring shows up are mass edits. Recently there seems to be a spate of them and some are harmful and annoying. When someone replaces a misspelt tag that is helpful. Changing Name=* to name=* or buildng=yes to building=yes would both benefit the object. However that is not what many mass edits are about. Some seem to be about homogenising the data, replacing the value part of tags with something generic. Sometimes a tag is removed and a replacement tag is added in its place.

I challenge the people who fire off these homogenising edits, which I dislike. The commonest excuse is that the wiki says the tag should be like this. This is infuriating. The wiki is full of controversy with edits chopping and changing the meaning of a tag back and forth. The open part of OpenStreetMap can be interpreted in many ways, and one way is that the tags that are used are open, that is any tag key and value is allowed. I also hear that TagInfo shows that value x is the most popular so every object must be changed to x. What TagInfo actually shows is that there are many uses of the key and that x is not the only way to use the tag, so why should they all be forced to be the same?

The second reason quoted is that how can the data be used if it is not consistent. Ontologies are mentioned. The odd thing is that people who say this are not the people who use the data for rendering, routing, analysis or whatever. The OSM data as derived from the API as XML (or pbf) needs to be processed to be used. That processing often loads the raw data into a database or processes it into a working file and that loading process can include catching a range of values that are useful for the render, analysis or whatever. If the variations of the key values are useful then they are used, but if some mass edit has flattened out the data into a monotonous grey, then those differences are not available. This processing will be a few lines of code, written once and used over and over without harming the detail at all. This is how landuse=cemetery and amenity=graveyard can be treated as the same thing or treated differently.

I know that a carefully chosen tag that gets splatted into some other meaning by a thoughtless mass edit is annoying. If that annoyance persuades a mapper to stop contributing to OSM that is a problem. Our most precious resource are our mappers and if a mass edit risks losing just one of them then that is a very serious indeed.

I have been accused of not wanting objects I created being changed; of being too protective. I'm not and that misses the point: OSM is a wiki. The objects are all open to edit every day. I just want those edits to improve the quality not squash it out.

New development for Hull

2012-01-13T19:41:00.001Z

Yesterday we went to see the plans for an exciting new development in Hull. Kingston upon Hull sits alongside the Humber estuary and has docks along much of this waterfront. Some have been changed over the years - one has been filled in and turned into a sunken garden in the city centre, another filled in and and turned in to a housing development, one has a large shopping centre built over it on stilts, one has become a marina, but the biggest ones remain as commercial docks run by Associated British Ports. ABP have announced plans with Siemens to create GreenPortHull, a factory to build offshore wind turbines to be installed in the North Sea. The existing Alexandra dock will have the companies who use it moved to the next dock, King George dock, so that the whole of Alexandra dock can become GreenPortHull.

I talked to a helpful guy from ABP about the development and explained about OSM, which he seemed genuinely interested in. I decided to use his description and his flyer to create a mock up of the new GreenPortHull.I first rendered a small map of the way the dock looks now:

I then copied the data and edited the copy to change the shape of the dock area, alter the road, remove the footway and add the new cycleway around the north of the dock. I added a few captions (by cheating with adding some place nodes) and rendered the new map.

The result is interesting, and done in a few minutes could be a bit slicker, but with more time it could easily be great.

The development is almost universally welcomed in the city which should be building turbines in three years.

Plaques, blue or not

2012-01-10T17:19:00.001Z

I came across a reference to a blue plaque recently and found openplaques in the process. Blue plaques get put up to commemorate something or someone. I somehow assumed that they were only in London so I was surprised to find 60 in Hull. When I looked a bit further there seems to be some in East Yorkshire too, including 25 in the small town of Howden alone. This is just something else to look out for in our travels.

We then discovered that the next village has at least one (pictured) and maybe more judging by the heritage trail inscription. If I want to add these to OSM, and why not, I wondered what tags to use. The plaques are marking something of historic significance; something happened here, or someone special lived or worked here, or a building of significance is or was here. The historic tag seems appropriate, but what else? The Map Features wiki page lists many historic tags, the closest seems to be memorial, but that is not really what the plaques are. It does suggest it can be a 'plate on a wall', but I wonder if historic=plaque or historic=marker might not be better. I have used historic=memorial with memorial=blue_plaque too.

I have emailed Jez at openplaques.org to discuss this. He suggested connecting the OSM object to the openplaques object, which others have thought of too, especially Mappa-mercia. I like this idea, but as always there is no generic way to do this. I have used openplaques:id=* for now. Jez suggested ref=openplaques:id=xxxx. At first I liked the ref idea, but it is not verifiable on the ground - the id is not written on the plaque because it is made up by openplaques not the people who put them up. I think ref=* should be verifiable. I also don't like the extra "=" sign. I wonder if OSM needs a link_ref tag as a general linkage to outside references. That could be link_ref:openplaques=1234 but also link_ref:ERoY=xyz if the council (East Riding of Yorkshire) have a separate reference too.

It is important that databases outside of OSM do not expect OSM IDs to persist. It would be tempting to reverse the process and have openplaques store the OSM node id of the plaque, but these id are not guaranteed to remain unchanged. In the case of a blue plaque it is unlikely to be redrawn as a building described by a way rather than a node, but other objects certainly can be.

If you have plaques (blue or otherwise) near you to commemorate someone or something why not add them to OSM and openplaques.org. Then we can all ~~argue over~~ agree what tags to use.

A snap

2011-12-22T16:35:00.000Z

Today is the winter solstice here - the north pole was tilted directly away from the sun at 5:30 UTC today. This means the light level is low and the sun's angle is low, so photography has extra challenges. As we drove along a lane near Old Ellerby a sparrow hawk flashed along the hedge and whizzed across the road. I expected it to disappear, but it landed on a fence and stayed long enough to stop and snap a quick photo. The low light didn't help, but it is recognisable.

'Plane crash

2011-12-17T18:25:00.000Z

We made a short trip out to eliminate some licence issues. It was a bright, cold winter's day with a lot of traffic on the roads (is there something going on?). We gathered the data to remap an area and headed home by a longer, quieter route that sticks to country roads. The light was still quite good, but in a field Jean saw an aeroplane that looked odd. I stopped the car and saw immediately the reason it looked odd was that it had crashed. It looked like a Piper. I called the police and while I did so another car pulled up. As it happened the driver was a paramedic. He went to the plane and contacted his control centre and was told they knew about it and no-one was hurt.

When I got home the police called to say the plane had crash-landed with engine failure and no one was hurt. Looking at the map the nearest airfield from the crash-site was less than three kilometres away at Mount Airey farm, maybe the pilot was trying to get there and didn't reach it. Having landed a plane there myself I know it is a small, tricky airfield with a sloping runway and a lot of trees around and it's not often manned, so not a great place to land with a problem.

The plane is probably a right-off. The starboard wing and engine look damaged. Looking up the registration it is a Piper PA 23 Apache and at least 35 years old, though planes that old are not uncommon in light aircraft.

Not quite an average mapping session.

Ducking the wrecking ball

2011-12-14T20:53:00.000Z

The long saga that is the OSM licence change process is picking up pace again. The plan now is to move to the new licence on April 1st next year. That will mean that anything in the database needs to have been added by someone who actively accepted the new licence and contributor terms. So anything else will be archived and removed from the live database.

Declaring the date has been like a light to moths for the few but vociferous deniers. Spreading FUD and generating bonkers conclusions from scraps of truth continues to be their main weapon against the will of the majority. Tricks like calling the change "the deletion" would be worthy of tabloid journalists. One tactic seems to be neither accepting nor declining the new licence to continue to spread uncertainty. I respect people's choices, I deplore the underhand tactics. The LWG continues to hold the high ground of not responding to the provocation.

I have been reviewing the area I'm most interested in, so that by next April there will be no problem areas here. The first weapon is to simply get as many mappers to accept the new licence and CT. So far everyone I have contacted have happily agreed. I have been as neutral as possible in contacting people, not wanting to agree is very much their choice and I respect that. The problem remains that a few people are not responding to messages sent to them. The main reason I suspect is that the email address they registered with is no longer valid. They may have used a work email address and no longer work there for example. I have tried to find people with Google+ accounts, Facebook and Twitter. I've searched for people by name in an area with Google but so far a few stubbornly remain as unresponsive.

There are a few objects created by people who have declined the new licence. These are easy to deal with: simply remap them. I risk losing details added later by acceptors, but having reviewed the bulk of the stuff, the loss is minimal. Indeed, gathering what I normally gather sometimes adds more than is there now, such as speed limits, weight restrictions, bridge heights, lit and so on. I'm leaving some stuff added by people I haven't been able to contact yet, in case they accept. I expect that there will be some places to replace, but I don't mind that. Some of the footpaths will take longer to replace and some will be easier with the better weather in the spring and summer.

I will be remapping stuff created by the FUD mongers too. If they accept at the last minute (which I doubt) there will be nothing of their work left to see, which will be a shame. I was out today gathering some traces and photos (in the gathering gloom) to start that process. I will be happy and a bit smug when I see an email on the lists that is clearly trying to be a wrecking ball and I know that my area is free from such problems.

2011-11-28T16:23:00.001Z

We paid a quick visit to Woodmansey today to check out a holiday home park that has been in the press recently and some other stuff. Apparently people have been living in the chalets all-year-round when the planning permission doesn't allow this. The place used to be a caravan site but now the caravans have gone to be replaced with smallish chalets on brick foundations. There were still plots for sale and the sales office is still advertising them as retirement homes which is not what the planning permission was for.

The road ways have names and all showed up on the OS Locator anomalies list. We gathered much more information than just the road names: there were more named roads than OS locator indicates, one road name was wrong in OSL, there were a couple of lakes and a public footpath running through the site. It is always worth visiting the scene of these anomalies rather than just use the names, sometimes overwriting the existing surveyed stuff as has happened in the north of the county recently.

A few service roads and buildings on an industrial estate and a couple of extras added, including a newly-built gated community that I sneaked into while the gates were still open for the builders rounded off the visit. On the way home we found a new 40 mph speed limit on a very quiet, narrow and twisty road that is often used by cyclists and horse riders. There was also a bunch of notices up about compulsory purchase of land to the south of Beverley where a much talked-about southern bypass is in the planning stages. It seems a bit bold to compulsorily purchase the land when the planning has not been agreed and there is still, therefore, some debate about the exact route.

Highest and Tallest

2011-11-18T16:51:00.002Z

We took a ride to the top of Garrowby Hill on the A166. It was a bit wet in the unforecast rain, but it stopped long enough at the top of the hill to not see the view for the murk. This is the highest point in East Yorkshire at about 245m. We did find the trig point hidden away in the grounds of a small water works. I added the runaway lane on Garrowby Hill, but I don't know what others tag these as. I'll probably have to change the tag when I've worked it out.

On the way home we passed Market Weighton and noticed that the bypass has a new name: Giant Bradley Way. William 'Giant' Bradley was the tallest British man ever recorded at 7' 9" (2.108m). Market Weighton, where he was born and lived, is trying to use the Yorkshire Giant to promote itself as a centre for tourism. Which is nice.

Why don't Google credit Ordnance Survey?

2011-11-12T14:21:00.002Z

I've been out checking names of OSM roads. ITO World's OS Locator tiles help to find the places where OS Locator and OSM don't agree. Often on rural roads the names are missing from OSM because there is no name board, but sometimes there are name boards and the difference is because OS Locator does not agree with the name board.

Normally I don't look at Google maps - I'm not interested. Their marking scheme clearly is different from OSM because farm tracks show up as roads for example. When I did look at a Google map page that someone linked to I noticed that an OS Locator name that is wrong on the ground appeared in Google maps. Recently I've checked a few more and whenever OS Locator disagrees with my findings on the ground, so does Google maps. In a couple of occasions OS Locator disagrees with OS StreetView and Google matches OS Locator. I have also used Google's StreetView to look at the name plates where they exist and sure enough the name plate disagrees with the road name on Google's page. Google have the photographs to show the real, on-the-ground names in the StreetView system, but they haven't used them.

Some people might say that the OS names are correct and the name boards might have errors, but I strongly disagree. When the council replaced some damaged name boards locally and one was wrongly spelled, there was a fuss from the people who's road name had apparently changed. They insisted the council put it right, and the council did replace it, though it took nearly three months. My point is that if a name is wrong on the ground people will have it corrected, but if the name is wrong in an OS database no one complains so it doesn't get corrected.

When it comes to Google's naming of roads, the only conclusion I can come to is that somewhere in the supply chain of data that Google uses, OS Locator or some similar OS data is used. Google, or one of their suppliers may have an agreement with Ordnance Survey, but if they are using the open data I wonder why they don't attribute OS?

By the way, why did OS choose "StreetView" as the name of one of their hurriedly-put-together OpenData when Google already used the name for a quite different product?

Wifi coverage maps

2011-10-31T18:33:00.001Z

I have been working on a small project for a Community Interest Company who deliver Fi-Wi and who want to display the coverage area of their wifi. They want to show the coverage as bands for their speed of connection: 10Mb, 20Mb, 30Mb etc. They cover a number of areas across the country, especially rural areas. I needed to display a polygon over an OSM map. Their website already has a map on it, using Cloudmade tiles, but with no coverage area on it yet. I took a look at GeoJSON as a way to handle description of polygons and looked at the way OpenLayers handles it. I created a GeoJSON feature collection by hand and tried to display it with OpenLayers. After a frustrating couple of hours I hadn't persuaded it to display my polygons, so I turned to Leaflet. In a few minutes, starting from scratch, I had a map with my polygon on it.

I needed to manage many polygons so I created an AJaX feed to send a GeoJSON feature collection for a bounds box. That way when a map is displayed any of the polygons that should appear on it get sent for that map. The coverage polygons are stored in a database with their maximum extents for north, south, east and west which can them be used to decide which polygons are served for the current bounds box of the displayed map. As usual AJaX is quick and effective. Debugging is fairly easy too since a call to the AJaX server returns a GeoJSON file which is easy to read.

The remaining job was to create a polygon editor so the guys who manage the website can manage the shape of the polygons easily as well as adding new ones as their business expands. This was more intricate, though I'm not sure that I have yet done as much as I would like.

I've enjoyed working with this problem, I hope it helps the company. It has also convinced me that Leaflet is a much more pleasant way to display maps with overlays than wrangling OpenLayers, which may be powerful and very flexible but it always causes me problems.

Chasing names

2011-10-29T18:05:00.000+01:00

There is a list of roads sorted by county that compares the names on OSM maps to the names on the OS OpenData Locator. Chasing the names to get 100% is a bit phoney, but using OS Locator to find what is missing and especially if something has been added since the last OSM survey is very good. However much I think the name chase is phoney or even invites people to add stuff to OSM that isn't correct or surveyed, to make use of the idea that OS Locator help find new stuff, first you have to get a clean state to work from. The simplest clean state is to survey all of the roads that show up as anomalies and resolve the anomalies. In the process you see more details to add and things that have changed, such as closed pubs. I only add what I have seen for myself, though I will use aerial imagery and OpenData to assist with things like just what is the extent of that playing field that I now have the name of and can see is in use. Using OS Locator names for roads where the name board is not present is sometimes an exception, in that I have not seen the name, but I use it anyway. I do of course credit OS with a source:name tag.

Today we focussed on the southern part of the Holderness plain in East Yorkshire. It is a fairly flat area, with fertile aluvial soils making farming productive. The southern edge borders the Humber estuary which is miles wide at this point. Today the tide was out and the huge expanses of mud flats were exposed, which is what the wading birds like to feed on. The wild life is worth looking out for. It was a lovely place to take a break.

My aim is to clear Holderness steadily from the south, working past Withernsea towards Hornsea. I was contacted in the week by Stephen who mapped the whole of the town of Withernsea and then went quiet. He has now accepted the new licence which is very welcome; instead of starting again with Withernsea we can build on his good work and concentrate of places that need surveys, like Hornsea.

Kilham

2011-10-22T18:25:00.001+01:00

A bright, fairly sharp day tempted us out. I set off to check a few names in the Wolds village of Kilham, and in the end just about redrew it. The existing work was by a few people who had added bits that didn't join up, were very, very, approximate and had loads and loads missing. Most road names were missing even though there were clear names on every road. There was a name issue near the school. One end of the road has a board showing "Millside", the other "Mill Side". There is a change of speed limit on the road, so each end gets the respective name. It took a while, but it was a pleasant place to be. One thing us OSMers like is to find a substantial road that is missing. Seeing that GPS trace meander across an empty space is satisfying and today it happened twice for country roads, once where a rural road was marked as a bridleway and lots of times for small residential roads.

I usually draw areas such as sports grounds and school fields from Bing imagery when I can, but a very new recreation ground was just a field on Bing. I had to guess how much of the field was taken. There was also a short road with a few brand new, empty bungalows on it. The road has no name board and doesn't appear on OS Locator, so I left a fixme for the name.

On the way home I we passed some road works, with a footpath / cycle lane next to the road. There was a sign giving orders to cyclists. Clearly the person who erected the sign doesn't know the rules.

2011-10-04T17:08:00.000+01:00

The end of the strangely warm start to October saw us out onto the Holderness Plain looking for names of roads and any other stuff worth improving. Once again we discovered a road name that Ordnance Survey have just made up without checking what is really there. There is a road called Fox Covert Road just north of Otteringham. There is a sign which is not new, but is perfectly readable.

OS call the road Whinhill Road. The road is a minor lane which only goes to a couple of farms, the second of which is called Whinhill farm, so I guess that's where OS get the name from. Nearby OS show a road called North End road and there is a farm called North End Farm too, this time no sign boards to confirm or deny this. The road from Otteringham is called Station Road because it headed to the abandoned station on the Withernsea line, which fell under Dr Beeching's axe. The place where the name changes to North End Road is not clear, but near the farm seems a good idea. I suspect the road may have been called North End Road long before part of it was called Station Road, but I can't be sure.

Of drain pipes and a polar bear

2011-09-05T17:02:00.002+01:00

The junction of Princes Avenue with Spring Bank and Spring Bank West in Hull has changed a lot over the years. There used to be railway line scything across the junction but Dr Beeching saw that closed down. It ran to Hornsea and part of it is now the NCN 65 cycle track, though not until further east in Hull. On the south side of the junction was one of the first botanical gardens in the country, that has since become Hymers College in about 1890. The railway crossing was known as the Botanic Crossing long after the gardens had become academic. The road junction used to be a police- then traffic warden- controlled junction before traffic lights took over. The shape of the junction was better suited to human control than traffic lights, but it has taken thirty-odd years to redesign the junction to be better suited to the lights.

In nearby Beverley Road there used to be a pub called the Zoological Hotel marking the zoological gardens on the north side of Spring Bank. The pub shut down in the mid eighties. In the mid nineties the name was revived; the Old Zoolgical pub was built to replace the Botanic Station building. The station car park was where the coal yard used to be for the railway. The new pub, called the Old Zoological, is nearer the zoo than the old pub was.

The shape of the buildings shows how the road from Princes Avenue curved gracefully into Spring Bank West, to avoid the railway crossing. The old name boards survive on the wall, either side of a drain pipe which seems to mark the change. The place now doesn't seem to be quite the right place for the street name to change because of the new layout of the road, but the addresses of the buildings haven't changed so the drain pipe marks the boundary.

Close by is The Botanic pub, which also marks the existence of the long gone botanical gardens. Opposite the aforementioned zoological gardens was the Polar Bear pub, named after an inhabitant of the zoo. Sadly, the Polar Bear pub stands empty today, The Botanic looks like it might be going the same way but the Old Zoological seems to be thriving.

New roads and a castle

2011-08-21T17:58:00.000+01:00

As the coverage of OSM improves, it is harder and harder to find roads other than small residential ones in East Yorkshire that are not in the database at all, but we found one today. It's always satisfying to see the red trace extending across the GPS in open space, showing it's a new trace.

We went to Skipsea, just south of Bridlington to see what was missing, quite a lot as it turns out. The previous mapper (tracer?) had used unclassified for residential roads, there were no road names, amenities like the pub, church, shop and school were all missing as well as most of the small residential roads, but of course it looked complete at a glance.

On the outskirts of Skipsea is a Norman church, All Saints. It was built fairly soon after the Norman conquest along with Skipsea Castle. The castle was a classic motte and bailey affair and all that remains today is the mound, now operated by English Heritage. The castle was built by 1086 but demolished on the orders of Henry VIII. Next time we're there I'm going to walk to the mound and take a closer look.

A bit more cycle route

2011-07-26T19:29:00.002+01:00

We discovered a section of cycle route signed with the NCN signs with the number 164. It seemed to be a newly opened route with the number 164. It seems to be part of a route designated the Yorkshire Wolds cycle route, but I didn't understand the numbering system.

We had followed a section from Beverley to South Newbald (see last post), so yesterday we then picked up from there, following the route onward. It headed through South Newbald and through North Newbald before turning up a rural lane called Stoneknowle Hill. The local council started to use a specific style of road sign about a year or so ago, so new signs are easy to spot and this sign is one of them. The road did not have a name tag in OSM, so I was pleased to add it.

The cycle route then leaves the road for a rather stony track, that in wet weather might also be rather muddy. This seems to be the only way of keeping the route off the A1034, which is not the safest road to cycle on. Another short stint on a quiet road and the route then crosses the A1079 - the main road from York to Hull which can be busy and carries fast-moving traffic.

Where did the 164 go?

The route coasts down a quiet road towards the disused railway line that runs from Beverley to Market Weighton which now carries the Hudson Way. At the T junction under the old railway bridge there was an NCN sign but not for the NCN164, only for the NCN66. I guessed which way to go and followed the signs for the NCN66 towards Market Weighton, but then realised that the signs had the 66 label on them but also Yorkshire Wolds. This is where the confusion lay and I only sorted things out in my mind when I had got home. The cycle route is called the Yorkshire Wolds Cycle Route, but it uses various numbered routes, including the 164, 66 and 1.

The route goes through Market Weighton, climbs towards Londesborough and into Pocklington following the NCN 66, before striking out again on NCN 164 again. At this point it is joined by the Way of the Roses, which is a coast-to-coast cycle route. This is the best part of the Wolds route by far, meandering through the rolling hills and valleys around Millington and up to the village of Huggate. Near Huggate we found a sign for another cycle route, NCN 167, which was signed as going to Malton, but exactly what the route is I don't know, so there's another journey to investigate. The NCN 164 now drops down a long gentle slope to Tibthorpe, which is where we left it to head for home.

Marbled white

Clustered bellflower

The route was very well signed, once I'd understood that it wouldn't be signed with the same number throughout. The scenery in the Wolds is wonderful, with views through the hills and out over the Vale of York and the Holderness plain. We saw some birds, including yellowhammers, linnets, swallows and goldfinches. We watched a marbled white butterfly flutter through the flowers, which included a clustered bell flower.

I would recommend a visit and I really look forward to investigating the rest of the route and the other route too.

NCN 164

2011-07-23T17:11:00.001+01:00

Out and about today in Beverley we stumbled on a new National Cycle Route, which it seems has recently opened. The NCN 164 circles the Yorkshire Wolds and has "Yorkshire Wolds" on the the bigger Sustrans signs. We followed a bit of it on a somewhat diverted journey home. I look forward to following some more of it, which seems to be a circular route mostly on rural roads.

If you are interested in a cycling in a quiet, rural space with gentle rolling hills, villages with B&B and pubs and wildlife still to be seen, try the Wolds. When this cycle route is added to OSM it will be worth following, but there are other delights in the Wolds too.

Docks and footpaths

2011-07-13T16:28:00.002+01:00


Shepherded between steel fences

Docks and public footpaths don't often mix. The modern dock area has to be secure, not only to prevent theft, but also to prevent unauthorised access to ships for people wanting to make unauthorised entry or exit of the country. The idea of having a public footpath running straight through a dock is a bit awkward, but there is an answer in Albert dock in Hull that is a bit unusual.


The walkway above the warehouse

The first part of the footpath is what you might expect, herded between steel fences to ensure you don't stray into forbidden areas. The next part goes over the lock gates, again carefully fenced to prevent any access to the main part of the dock.

The view along the warehouse roof

Then a surprise as the footpath mounts a steep set of stairs leading to the roof of a warehouse and the path follows a steel walkway along the roof of the warehouse to a short bridge and set of stairs that lead to the footpath along the outside of the rest of the dock. The view out over the dock and the Humber is pretty good but the novelty alone is worth the short walk from the Hull Marina to take a look at the footpath over the roof of a warehouse. You can see the map here.


A rather quiet Albert dock

Albert dock is fairly quiet now, mostly doing small refits on ships, including some large sailing boats. The view over the dock was particularly quiet today, but often there is a ship or two being worked on in there. The reason we revisited was to complete the footpath through the docks because the last time we tried the lock gates were open to allow a large ship out that only just fitted and since the footpath uses the lock gates we couldn't get across.

Crossing or not

2011-07-02T16:28:00.000+01:00

I noticed a small change to OSM close to home, so, as usual, I looked to see what the change was. A guy known as Valentijn had added a gate to public footpath and a comment about it being locked. I contacted him to ask about this and following his helpful message I went to see what was going on.

There is a public footpath on a paved track from Dunswell Road to the service road that runs around the Creyke Beck substation just north of Cottingham, as shown here. What Valentijn had found was that the gate either side of the railway crossing was chained and padlocked, and that was what I found too. There were the usual notices that Network Rail put up on unmanned crossings so it looked as though the crossing was intended to be used, but that someone had locked the gates. It seemed to me that the public footpath had been blocked so I contacted the local council.

I got a prompt and helpful reply from an Assistant Engineer (definitive map) who explained that the footpath only went as far as the crossing gates at each side of the railway and that the crossing was a private crossing for a local farm. He sent me a definitive map, but I haven't copied it here since it bears the Crown Copyright notice.

He went on to explain that the farm has had a road built connecting it to Cottingham (part of the work on the substation expansion I suspect) and so the crossing is no longer the main way of getting to the farm. After some incidents elsewhere in the country Network Rail's Health and Safety Team looked at all such crossings and put up gates where the public right of way did not cross the railway. It is entirely clear that the public right of way that no longer crosses the railway is completely pointless, but Network Rail have clearly avoided a serious health and safety risk.

I and countless others have used the crossing for many years with no incident but we have now been saved from our carelessness by the timely intervention of ~~the Muppets~~ the Health and Safety Team at Network Rail, to whom I am indebted for doubtless saving my life.

I have, however, made a useful and helpful contact at the local council and thanks to Valentijn the map is now a more accurate reflection of the real situation.

OS Locator and being thirty years too late

2011-06-08T17:02:00.000+01:00

In May the latest Ordnance Survey OpenData was released for OS Locator. This has been turned into something useful by Robert Scott in his Musical Chairs application and ITO World's OSM Analysis. ITO also provide a tile layer which I have used on my site, oscompare. These tiles get used in the editor imagery layers too.

The ideas of these tools is to show the places where OSM road names differ from the road names provided by the data in the OS Locator dataset. They both take a different approach, but both showed that two new roads had appeared in the OS Locator data that were not there before. We set out today to investigate them, and what we found couldn't have been more different.

The first road that OS Locator showed up was Stanmore Close. This area is part of the redevelopment of the Ings Road area of Hull. I have been anticipating needing to survey this area because some of the old council homes have been standing empty waiting for a bulldozer. When we got there we found that not only has the bulldozer done its work, but the builders are in busily replacing the houses. Some of the roads from Mitcham road, which were cul-de-sacs now join Mitcham Road with Camberwell Way. They have names ending in Close, but they are not now a close, however the names stand. I have extended all of the new roads that I could get access to, it looks like a bit more to come yet.

This is by far the best use of OS Locator in my book. It showed me that there was an area of Hull that had changed, I went out to check what had changed and improved OSM in the process.

We then moved to look at the second new road in the city, Garrison Side. This is an area I know fairly well, and I was very sceptical about there being any new road there. As soon as we arrived it was clear that something odd was going on. The site is close to the place the river Hull flows into the Humber. There was a defensive garrison built there in the seventeenth century, very long since ruined and disappeared. The road suggested by OS Locator would have been along the garrison boundary with the river Hull. A new river crossing over the Hull was opened in 1981 and the bridge cut through the place this road would have been. The photo shows one of the bridge piers slap bang on the place Garrison Side would have been. At the other side of the bridge there is a small remnant of a cobbled street in exactly the right place.

The last time it could have been there was before the bridge was built, so why has this obviously non-existent road suddenly appeared in the latest dataset from Ordnance Survey? If anyone needs reasons to check all the OS data on the ground before adding it to OSM, look no further. In fact if you're looking for Garrison Side you're thirty years too late.

Leaflet

2011-05-20T15:27:00.000+01:00

Vladimir Agafonkin announced that CloudMade have released Leaflet, a new open source JavaScript library for displaying map tiles as a slippy map. I've used OpenLayers up to now, so I thought I'd take a look at it.

I have a love-hate relationship with JavaScript. It is great that there is a powerful language that runs in browsers, but the environment it runs in is horrible: DOM, various browsers supporting various features, a fiddly run-time that makes debugging horrible etc. Firebug helps.

I decided that a reasonable test was to reproduce a slippy map page I already have to see how it works with Leaflet. That would help me compare with OpenLayers, but does run the risk of me using Leaflet in an OpenLayers way, which I hope I've avoided. It also only covers a small part of what Leaflet offers, but I seems like a start.

My page needs to display a slippy map with markers on it. A side bar will display details and photo for any marker that is clicked and a small message bar will explain the current situation. To get the layout I used a very simple HTML page and a simple style sheet. I tend to not embed styles in HTML or JavaScript, but to use either IDs or Classes to apply styles and declare these in separate style sheets, sometime more than one. I rarely embed JavaScript in HTML either, other than calling functions in events, so JavaScript goes into separate files too. All of these files are available to download, see the links at the end. The Leaflet JavaScript and style sheet are also included. The map is intended to show the locations and information about a series of sculptures around the City of Hull, as part of the Philip Larkin celebrations. They are no longer in place, but I had the data so I used it.

The first part seemed very easy: display a slippy map. The map is displayed in an HTML div. Ours has an id of map. The code to make the map appear is:

var map;
var hull = new L.LatLng(53.775, -0.356);
function initmap() {
map = new L.Map('map');
var osmUrl='http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
var osmAttrib='Map data © openstreetmap contributors';
var osm = new L.TileLayer(osmUrl,{minZoom; 8, maxZoom;18, attribution: osmAttrib});

map.setView(hull,11);
map.addLayer(osm);
}

That is a fairly simple piece of code to display a slippy map. The variables map and hull were defined outside of the function so they are available to other functions as global variables. The single most confusing part is probably the line

map = new L.Map('map')

The first part is a map variable used throughout the code. The second (L.Map) is the leaflet-defined object for a map. This defines how the map object behaves. The last part ('map') is because the div that displays the map has an id of map, which is in the HTML code. The URL includes {s} for the server prefix needed, {z}, {x} & {y} for the zoom, x and y tile coordinate. This allows various tile providers' tile structure to be used. Now the map needs markers.

Adding markers with Leaflet is very straightforward when you have the longitude and latitude for each marker. However, displaying a map with hundreds or even thousands of markers slows things down a lot, so I like to only add the markers that are visible in the currently displayed part of the map. You can get this by calling the getBounds() method of the map object. This returns the north and south latitude and the east and west longitude that describe the edges of the displayed map. Of course this can change as the slippy map is dragged to a new position or the map is zoomed in or out. So the way to handle this change is to respond to map events. The one which seems to fit the bill for us is moveend. This is called whenever the map is moved, including zooming. We supply a function that is called whenever the moveend event is fired. This is achieved by adding the line

map.on('moveend', onMapMove);

Now, whenever the the map is moved our function onMapMove will be called. In our example onMapMove simply calls the function askForToads() which gets the location of the markers we want. I use this extra layer of functions to make debugging easier.

We still don't know where the markers are to be placed, I do that by using AJAX to request the information about all the markers that fall within the bounds of the current map display. askForToads calls the getBounds() method of our map object, extracts the north, south, east and west coordinates and wraps it up into a call to a PHP routine that finds the list of markers and returns this in a JSON format. This returned list is processed by the stateChanged() function which is called as part of the AJAX process. The JSON provides a neat way to return this data, because simply calling eval on the returned string turns it into an array of, in our case, marker data. I then remove any markers already shown and recreate the new markers one at a time, attaching the data for that marker to a data field and recording each marker in an array (toadlayers.push). Working through the array allows me to delete the markers when the map changes.

You now need to respond to each marker that is clicked. This means that the click event needs to be responded to. This needs the line

toadmark.on('click',markerClick);

to ensure that any marker that gets clicked is responded to by the markerClick() function. Here the details from the data field are displayed in the side bar.

Throughout the process the message div displays messages about the progress of fetching the marker info and how many toad markers are being displayed.

This may seem a lot of work to display the markers, but we are making two substantial changes to the normal system of displaying markers, firstly we are only displaying some markers. If there were thousands of potential markers spread across a wide area this would make the process manageable by only displaying a few at a time. Secondly instead of just displaying a popup we are making something outside of the map div change, which opens up a wide range of actions.

How does this compare with OpenLayers? Most of it is simpler. OL provides an interface to AJAX which makes the process a bit simpler. It also puts a collection of markers together into a single layer which is easier to manage - Leaflet makes each marker independent so I had to keep track of the markers I had added. I like Leaflet, and for many things it is something I will use.

You can find the code examples on github If you want the database definition or even the data I can supply that too. You can see the working example here.

PSMA and open data don't mix

2011-05-14T10:57:00.000+01:00

I've been trying to encourage local authorities to consider using openstreetmap for a while on and off. It seems that Ordnance Survey (OS) recognised the growing competition and have forestalled these efforts. Local authorities use maps so much that they often have a dedicated GIS team. They base most of their activities on OS maps, which is not surprising, OS being the national mapping agency of Great Britain. Until recently the local authorities had to negotiate with OS about what products they wanted to licence. However the UK Government announced that this was to change for the current financial year and a new ten-year Public Sector Mapping Agreement (PSMA) was being introduced.

This agreement allows various public sector bodies access to core geographic datasets from OS, free at the point of use. This sounds very appealing to local authorities since they get to use any of the OS datasets included in the core set as and when they want and they don't have to worry about the cost. What could be wrong with that?

Well actually it is a very shrewd move by OS. The money to fund their licences with public bodies mostly came from central government. Most money that local authorities spend comes from central government. Council tax, for example, only covers about a quarter of local authority spending. The Government have naturally taken away the money they used to give to public bodies for OS licences and put it into the central pot to fund the PSMA. OS receive that cash, so they get the same money as ever, but now have much less effort in renewing the licences each year.

The really smart part is the way OS have tied the hands of local authorities into using OS datasets. When local authorities paid for an OS product, if they found a replacement the brave ones could have chosen not to licence the OS data and use the replacement instead. That would have saved them money - a great incentive. Now they get the OS datasets seemingly for free so why look at anything else?

Why does this matter? Well it matters a great deal if you are interested in open access to data from local authorities and other public bodies. If they want to publish information as text or tables they can do as they please, but as soon as they want to display the data as a graphic overlaid on a map their only option is to use an OS map as the background and suddenly they can't release the data as they choose because they are bound up by the draconian restrictions OS place on their map data. The local authority are not likely to use any other form of map, without these restrictions, because of the effort to move away from the seemingly-free OS datasets.

I am sure that for most of their work OS data suits local authorities very well. I'm not well placed to know if the PSMA is good value for money overall - clearly it is not free as some local authorities have claimed. I want to see a viable way of publishing data from a public body in an open way on maps that is not restricted by the licence of another public body, OS. PSMA has made that less likely to happen and has strengthened the hand of OS as a dominant GIS provider.

Another trip into the wolds

2011-04-23T21:48:00.000+01:00

The lovely weather tempted us out into the Wolds again. This time around Millington and Huggate. Last time we were in the area a few days ago we got talking to a guy with an expensive HD camera trying to film Red Kites. Today we saw him again. Last time we had rather too long a conversation which seemed mainly to convey just how money he has and actually convinced me that he has more money than sense. So this time we stopped somewhere else to have a drink and were pleased to see and hear a willow warbler.

The roads in the Wolds have very few name boards, even in the small villages. We found a few new, small residential roads that we had either missed before or were new. One thing I did see, which is worth following up on another visit, is the newly signed National Cycle Network trails. I understand that some of the existing NCN trails are having some sections renumbered where there are optional or alternative routes. This however is a newly designated route which I have yet to follow properly.

One of the roads that show up on the OS Locator tiles was Cobdale Lane. Like most of the roads is the area I wasn't expecting to find an hint of the road name, but I was wrong. The name started at a bend in the road and a pleasant cottage was set on the dip and turn in the road. The name of the cottage was Cobdale Cottage. A few hundred metres futher down the road there was Cobdale Farm too. Maybe the road name is Cobdale Lane as suggested.

Lovely day in the wolds

2011-04-19T18:37:00.000+01:00

The rolling hills of the Yorkshire Wolds is close to home and is a constant draw when I want to fill my lungs with fresh air. We went out today for a simple ride out, but I couldn't resist checking a few things for OSM. There's a roundabout near Pocklington that is being built - the road now used the roundabout in part at least. There was a small road that has altered in Shiptonthorpe. The main event today though was the scenery bathed in sunshine. It was about 21°C which is certainly warm for mid April.

We looked out for birds at the spot pictured as we enjoyed some tea. We saw distant red kites and buzzards. I heard a green woodpecker a few times, but it remained stubbornly hidden. I think I'll be back, if only to catch a glimpse of that woodpecker.

More villages and lint chasing

2011-04-16T15:53:00.000+01:00

A couple of years ago we added what we thought was the last road to OSM within the boundary of Hull. That turned out to be a bit optimistic, but fairly close to the truth. We have taken much longer to move towards completion of the East Riding of Yorkshire. There is a still a long way to go, with towns like Bridlington and Hornsea still requiring a bit of work and a few largish villages still needing attention. The countryside is pleasant and now the spring is arriving with blackthorn hedges bursting into better shows of flower than I remember for many years.

Recently we have surveyed Beeford and Brandsburton. Both were easy to do, but the difference in the ambiance in each village was marked. Beeford was pleasant, Brandsburton was distinctly odd. The list of villages needing their roads and basic facilities mapping in East Yorkshire is now probably about 40, and some are tiny needing only a brief, passing visit. There are still surprises though. We found a secondary road heading out of Beeford which was not mapped. I need to check if there are any more that need adding in the county.

The process of checking roads has been assisted by the release of Ordnance Survey's Locator data. This defines a bounding rectangle and centroid for every named road in the UK. This has proved particularly useful in settlements since it shows up roads that are newly added in an area since it was surveyed. To get this I use the highly useful transparent tiles that ITO World produce. I added them to my own overlay, which now also includes postcodes at high enough zoom levels. The OS Locator data is also available in OS Locator Musical Chairs.

Like all lint tools there are some drawbacks, the main one being that people are tempted to just use the name from the OS Locator dataset rather than going out to check what is really there. On many country roads there are no name boards and OS Locator is usually right, but even so I prefer to go and look before using the OS name. At this time of year the ride out is always worth it.

Lint tool providers have a duty, in my mind, to be as impartial as possible. They can wield quite a lot of power in the way they chose to flag up errors. Many people quickly adopt the scheme as the standard way to tag and there is a flurry of activity to reduce the 'errors' for their area. Recently there has been some discussion about the way national speed limits are tagged. I strongly believe that tagging schemes should be designed to assist the surveyors and mappers, but some seem to think that the consumers of data should be treated preferentially over mappers. Here's why I don't agree:

There are never enough mappers in an area. Attracting them and keeping them is hard. An overly complex tagging scheme means they will quickly get fed up. "All that just to add a speed limit? No thanks."
Complex schemes mean mappers make mistakes. These are then likely to be 'fixed' by some bot or mass edit. These are not done by mappers who have visited so surveyed data can be lost or changed.
Mappers must use a tag over and over again, each time they encounter the thing that needs tagging. Complex schemes means adding many tags for one object every time you see it which increases the mapper's workload.
Programmers write code to recognise and use a tagging scheme once. The map or analysis or whatever that they produce can then be run over and over again with little or no effort, consuming the tags that mappers took hours to add.
Retrospectively increasing the complexity of tagging for a commonly encountered object, like a speed limit, means you are asking people to resurvey huge lengths of road. If you don't need a resurvey then the increased complexity is not needed as it can be inferred some other way in a program.

One thing I have noticed and has been commented upon elsewhere is that many of the people suggesting that data consumers need this tag or that tag to make sense of the data have never actually tried to used the data in a program. They have no idea what is really involved and what techniques can be applied to get around any problem.

Fairy land

2011-03-25T11:02:00.000Z

Another string of pronouncements have been made on the Talk mailing list by the ODbL deniers about why OSM should not accept the new licence and contributor terms. Grant despairingly wonders why they should come to these conclusions.

People come to these conclusions because it suits their agenda, not because of the facts. Why let a carefully written licence and all of the discussions that have gone before get in the way of a good conspiracy theory? The world is full of conspiracy theorists and FUD mongers; the fact that OSM attracts them simply shows the project is big enough to attract the cranks as well as the serious.

Some people will always glaze over when confronted with a big blob of words, whether that's a licence agreement or something more important like an explanation of how dangerous radiation is. They then seem to go off into fairy land, inventing fearful scenarios and outcomes that are wrong. Doing thought-experiments is a great way to test the limits of a licence, but you have to keep checking that you have not exceeded the bounds defined by the licence otherwise you end up in fairy land.

I fully and wholly respect anyone who has an objection to the licence change and who wants to use the CC-BY-SA licence as it is, I just haven't been convinced by their arguments. What I don't respect is the underhand way some people undermine the licence change process by spreading FUD and untruths about what it means and the way the project will work when the change is complete.I support the change to ODbL. I believe it will benefit OSM, but even ODbL is not powerful enough to drag everyone out of fairy land.

HU14

2011-03-24T20:53:00.001Z

We've been working on addressing close to home. Bing aerial imagery came along and I realised that although Bing is not as good here as elsewhere, it is just about good enough to trace buildings. I traced a few buildings and then took the existing addressing and applied it to buildings. It was much better, so we gathered the remaining addresses for Swanland. I then tried to gather all the addresses for nearby Melton in a day (and didn't quite manage it). Then Blackadder announced he had completed a whole postcode, and I realised that I was more than halfway through HU14, so I just had to polish off North Ferriby. Just! What was I thinking about.

I decided to try Blackadder's scheme of drawing the gardens too. That means working out where the boundaries of private gardens are. This is harder to work out than it may seem. Some are masked by trees, some of the photography is a bit blurry and so on. Then there's the age of the photography - about ten years old. A lot has changed in ten years. I have had to use OS StreetView for a few areas where new housing has been built since the Bing photos were taken. I have tried to represent the differences between hedges, fences and walls as best as I could. I tried to take note of hedges or fences as we wandered around gathering the addresses. My verdict on drawing gardens: DON'T. It is a pain and makes the difficult job a lot harder.

Gathering the addresses seems a bit easier, it's probably just that we can do it on auto-pilot. I draw the buildings as blanks before we gather the addresses, we can then write on the real addresses as we go round and sketch in any additions. It is still a lot of work. You can see more here.

I'm not doing any more addressing for a while, but I think I will do some more again. The prospect of gathering the addressing for the whole of Hull is overwhelming and would take years.

Naming country roads

2011-03-18T20:03:00.001Z

A lovely day tempted us out, first to do some jobs on the allotment, then trying to resolve a few names on the country roads. We found a couple of small residential roads missed on the first pass. We found two war memorials, a small church, some allotments and a village hall previously missed too.

Before we went out I spotted something we've seen before, or so I thought. There looked like a road name on OS locator that looked like it was really the name of a farm. There is a road called Highgate heading west out of Cherry Burton, which is well signed. OS Locator shows a small section of road called "Dunken Hill Highgate". I expected to find a farm called Dunken Hill and that the same mistake as we have seen before, that is an address has somehow become treated as a road name.

We found the farm called Dunken Hill, exactly as expected, but when I got home I looked at OS StreetView. It shows the road name as Dunken Hill (without the Highgate bit). It shows the farm name as Dunkenhill Farm. There is also a nearby area also labelled as Dunken Hill and the road crosses part of the edge of it. There were no signs, but I decided to accept the OS StreetView name. The OS Locator still seemed muddled and being different from OS StreetView is something that happens. If anyone knows better I will accept their wisdom or knowledge.

I'm not actually too bothered about some of these country road names, the roads are there, there are no houses or businesses on many of them except farms and they have names of their own. Many country roads have no name boards, so using the name to navigate isn't actually possible on the ground. Making sure the missing roads are added is much, much more useful, but hunting down road names can be an excuse for a pleasant ride out.

Shared building, two streets

2011-03-07T12:46:00.000Z

I have been gathering addresses and other detailed information for the villages that make up the postcode area HU14 - more of that soon. One thing I noticed in a few places is where a building that makes up a semi-detached house is on the corner of two streets and each house is on a different street. Having thought about it there is no real reason why both houses in a semi-detached should be on the same street, I just expected that they would be.

The highlighted houses in the picture are especially confusing because their numbers are so close, but one is on Riverview Avenue and the other on Southfield Drive.

Who needs approval?

2011-03-04T18:52:00.000Z

I have seen discussions about what tag to use since I first joined OSM and it's not always easy to understand. Some things seem obvious like tagging a road. It's a highway right, so highway= ... ? Residential is fairly easy (but is it a living_street), but is a substantial road a trunk road or a primary, or even a secondary? Is a small road a service road, a track, an unclassified or even a path?

How do I tag a church? Apparently it's not a church, it's a place or worship, so then it needs an extra religion tag to differentiate churches from temples from synagogues etc. Why not just tag it a church or a temple?

Areas of land are unfathomable. Some get the landuse tag, i.e. how the land is used such as retail or commercial. That makes sense, but then along comes landuse=grass. Not 'used for grazing' or 'used to suppress weeds', just landuse=grass. Hmmm, does that work?

So it seems that somewhere in the past a plan was devised to sort this out: an approval process. New tags would be proposed, discussed and commented upon and then voted on, so tags would be approved for use. Approved tags? What's that all about? There are no approved tags, anyone can use any tag that suits their purpose. That's at the core of OSM and part of what makes OSM so successful.

Imagine what would happen if I couldn't use any tag I want to. Picture the scene: I come across something that is not in the list of approved tags. I want to add it to the map. I have two choices, 1) add it as something else that is in the approved list but that is not what I have seen or 2) I can walk on by and not add it until it is in the approved list.

Both of these are stupid: option 1) will show up as the wrong thing until the tag is approved. What if the tag is not approved? Will I remember to remove it? How will I feel about removing my hard-won object?

Option 2) is even worse. The object will not get into the map database. So not only will no one looking at the map or database know it is there, no one will know there is such a thing waiting to be added, so when (if) the tag is proposed no one will know how many of them there are waiting for the tag. Will I go back and add it to the database after the tag has been approved? Somehow I doubt it, more likely I would be fed up with the bureaucracy of the process and will have left the project to give my time to someone else.

Then there's the thorny question of who should be the one to approve these new tags? No one owns OSM, so there's no one to appoint an approver. How do I know what it is you are interested in or what you want the map to be about? I don't so doesn't that rule me out from approving your tags? That effectively rules everyone out from being the approver since no one can understand everyone's motivations, so next you need a committee to try to cover more interests. How big will the committee need to be? Who sits on the committee? Am I allowed to vote someone on/off it? Why? What gives me a vote? Do I get a vote because I have been in OSM for six days? Six months? What if I have only changed a single road name in that time? So maybe I get a vote because I've added a thousand nodes. I could just add loads of nodes into existing roads just to get my vote. Can I buy a vote in return for a donation of ten dollars? What about 10,000 dollars?

So even if some sort of committee gets formed, how often do they meet? Will they need to get advice from other experts? So how long will it take to get a tag approved? When they do decide to turn down a tag will there be some sort of appeal process? What if that is challenged by a rich company that wants a tag approved and who has a large legal team?

How will people be bound by any of this? Clearly they will have to agree to this, so as well as signing up to a licence for the data, they will have to agree to be bound by the Approvals Committee. How many people will agree to that?!?

So the answer is simple. Allow people to use any tag they like and allow a process of natural selection to merge disparate tags together as a consensus develops. Publish a list of tags that are widely used based on statistics. A description of how people have chosen to use it would help other people decide if they want to use it too. A list of the tags supported by some of the main data consumers such as renderers and routers would help too.

If this the right way to do it, then why does the approval process exist? A very good question. I don't think it should not be there at all. Removing the process would remove the right of passage of creating a tag. It would stop the stupidity of someone creating a tag, getting it through the voting process by a few people voting to approve it and then claiming it is an approved tag and demanding it gets rendered even though it has hardly ever been used. It stops people voting for or against a new tag even though they have not used it, have no knowledge about the subject and only voted because someone invited them to do so on a mailing list.

So I do sometimes struggle to find the best tag to use, but I'm relaxed about that. I am not at all happy about the phoney, abused and irrelevant tag-approval process and I would like it to end now.

House or road

2011-02-12T18:20:00.000Z

More name checks today, the target was the Barmby Moor area near Pocklington. As we have seen before, the OS Locator data is very useful. It showed up a few small new developments in Barmby Moor. It also showed up a number of oddities which we have sorted out.

When I originally surveyed Barmby Moor we did it quite quickly and some street names were missing. Today I wanted to correct that. One area that was a bit awkward was the main road through the village. It only bears a name plate at the north east end, where it says Front Street. According to OS Locator it is called Main Street. We couldn't see any other name boards, so if the name changes it was difficult to see where. I looked at the house numbers for clues, but for once that didn't work - the houses have names and no numbers. I decided to ask the locals.

A very helpful elderly chap was tidying the garden of his bungalow and he explained, at some length, how the name of the street had changed in his lifetime. He explained where Front Street changes to Main Street and how, when the bungalow he lives in was built 30 years ago, the end of the street became West End. Sure enough the few bungalows at the end of the street have a numbering scheme that fits.

The main A1079 that runs by the village is called York Road on OS Locator. There are no signs to that effect that I can see, but it does go to York. Oddly there is a small piece of the road that seem to have a name Gale Hill within the section that is also called York Road. Looking closely I spotted a house called Gales Hill in just the right spot. I have seen this elsewhere with OS data. Near Molescroft there is a road OS think is Constitution Hill, but that is the name of a nearby farm. The road is called Malton Road, I know someone who lives there.

If you are using OS Locator for road names, beware of surveyors who can't tell a house name from a road name.

Sympathy

2011-02-11T16:23:00.000Z

I like the tools that encourage people to get out and look at their surroundings. Some might call it surveying, but often it's just an extra to some other journey or visit. Sadly some people don't get out and look what's there, they just use the tools to blithely add data to the OSM database regardless of how up-to-date it is or how valid it is.

Today we wandered around part of the East Riding looking for names where OSM and OS Locator don't agree. The rain had stopped but the promised brightness didn't appear. I found a new housing development with a few houses on it developed since our last visit (one of the best uses of the OS Locator dataset). We found a couple of roads OS Locator has names for where we couldn't see a name and a few roads where the OS Locator data was wrong. Coppleflat Lane seems to be everywhere and actually it is nowhere. I think the OS surveyor (or whoever they got their data from) must have had a bad day.

I toyed with venturing down a named, very muddy track that we didn't have a trace for and decided that a trace from Bing, well aligned with our GPS track would do. The Bing photos are a bit old, but I estimate the track is hundreds of years old so they will do nicely.

One name I didn't know was Bluestone Bottoms. I can feel some sympathy with the road - this hard chair that I'm on now leaves me feeling a bit like that sometimes.

A whole village?

2011-02-04T19:04:00.000Z

We took a tour around Melton, a small village not far from home. My aim was to add all of the addresses for the place, from collection to editing, in an afternoon and I failed. We wandered around the place in a howling gale, struggling to see some of the addresses. The addresses of some houses which don't display a number can be determined just by looking at the number either side, but on some of the older parts of village streets that doesn't work. Some houses only have names, some are recent additions to the street and the numbers don't fit and sometimes there are gaps in the numbers for no apparent reason.

We completed the whole village quite quickly. Except we didn't - I had forgotten that part of the village lies to the south of the A63. So, addresses for a village in an afternoon? Not quite.

Binary files

2011-02-02T16:43:00.001Z

I have downloaded lots of OSM data from the API, XAPI, the Export tab and from other sources such as Geofabrik and Cloudmade. This has usually been XML files which are often compressed and are easy to understand and deal with, if a bit bulky. The ubiquitous XML format means there are XML parsers available for the languages I use and choices in the way of approaching parsing depending on what you are trying to do, though XML parsing remains a fairly slow process especially given that it is rarely an end in itself so the real use of the data cannot start until the XML has been deciphered.

The volume of data for a given area has steadily increased as detail has increased and the one thing XML is not good at is being compact. The process of moving OSM data around involves moving data across networks and this is sometimes a slow process - my own broadband is not very quick and I have no choice of supplier so there is no competitive pressure to improve the performance or the dreadful customer service, but that's another story. One way, potentially, to improve this is to use a binary file format which could be much smaller even than a compressed XML file and might be quicker to encode and decode. Such a format has been created by Scott Crosby based on the Google Protocol Buffers (protobuf). The files are known as .pbf files.

I have not used the protobuf file formats before so I read the Google pages which seemed to make some sense, though the examples are simplistic. I turned to the OSM wiki page describing how Scott has created the protobuf layouts and it left me baffled, so I looked at the source code of various utilities that now incorporate support for .pbf files.

I wanted to write something using a .pbf file and, having done this kind of thing before, I know that it is easy to copy other people's code and use it without really understanding it; understanding the use of the .pbf files was an important objective for me. Google provide direct support for using protobuf in C, Java and Python, but there were no Python OSM examples to be found, so I decided to start by writing a Python pbf parser so I couldn't just copy someone else's code verbatim.

I downloaded a .pbf file from Geofabrik to work on. Examining the layout of the file was not easy. If you try to use a hex viewer things are not clear because chunks of the data can be compressed and even uncompressed parts are difficult because the protobuf format squashes data, especially numbers, into the minimum number of bytes to save space. Most of the text used in tags are in a string table, so each string only occurs once in each block of data. In the end I simply wrote code to work through the file extracting and examining each part step by step. The OSM wiki page did help in some places, but I got most help by looking at other code, the protobuf definitions and the Python files the protobuf compiler creates.

I now have a Python script to parse .pbf files, so I can use the data in the same way as I would having parsed it from XML. I have used the Python OSM classes that I created some time ago to store the data so I can write XML as a quick test. If you are interested in seeing the result of my work you can download it from here.

Footnote:
I have tried to parse the downloaded file for England from Geofabrik. It couldn't load all of the nodes in my 3Gb memory and was killed. I removed the code to store the nodes, ways and relations just to let the code run through the whole file. After more than two hours it had run through, but I couldn't have done very much with it as none of the expanded data was saved. It works well for a smaller area, such as a county or a city, but it doesn't handle big files very well at all.

Surveys

2011-01-25T16:11:00.000Z

This mapping makes me notice changes that I think would have washed over me before, but I'm sure I would have noticed what has happened to Heron Foods warehouse. They have moved to a shiny new warehouse outside of town and the old one has been demolished, but I'm not sure what the plans are for the site yet.

It will be a while before any of the other maps display the site correctly, for me it is easy, I can just draw the building from the Bing aerials (the one with the mouse cursor on it) and tag it as a brownfield site until I know more. There is a fence around the site, where before there were the walls of the building, so I can add that too.

Rarely does a trip out not reveal something that has been missed or has changed, but not always such a dramatic change as this. Roll on the spring and the chance to do more surveys.

Using GB postcodes

2011-01-19T14:30:00.002Z

As mentioned in the last post I have been looking at the Code-Point Open data supplied as part of the Opendata released by Ordnance Survey. The data describes the centroids for each postcode which is given as a list of post codes for England, Scotland and Wales. There are about 1.7 million post codes in the dataset, broken up into CSV files, one for each top level code such as HU. Each file has a lot of fields with no data or dummy data in them, but the postcode and the easting and northing are what I need.

I wanted to make an overlay displaying the postcode centroids to see if they would be useful in working out the postcode for OSM addresses. Postcodes are part of the jealously-guarded Royal Mail database, sold as the PAF, which makes a couple of million pounds profit each year for Royal Mail. I would have liked to the detailed address data or at least the polygon that a postcode covers but the centroids are the best we have for now.

The process of making an overlay started by converting the OS eastings and northings to longitude and latitude. The original file is pruned to remove the excess and then I used gdaltransform to make the conversion, using the the OSGB datum EPSG:27700, before loading this into a database table.

Next I set about drawing a transparent set of tiles to use. I wanted to draw a dot for the centroid and the postcode as text beneath it. If I retrieve a list of centroids for the tile then any point close to the edge of a tile would have text that extends beyond the edge. The next-door tile, however, wouldn't know about that centroid so the text would be cut off. The simple way to deal with this is to draw each tile a bit bigger retrieving data for a larger area, draw the centroids and text then trim each tile to it's proper size. That way the text for points close to an edge will appear on tiles either side of the edge.

I rendered a set of zoom level 16 tiles for my local area and took a look to see how useful the centroid information is. It varies. For some roads the postcode is obvious from the centroid, some it is not clear where a postcode changes. I think it is of some use, so I pressed on.

I did not want to fill my on-line disk space with tiles that might not get used, so I decided to try creating the tiles on the fly to see if the response would be good enough. It is pretty good and local caching of the tiles helps too. I did have a small problem with the HTTP headers not wanting to work, but now that is sorted out. I can load the tiles as an overlay http://www.raggedred.net/codepoint/ and they work as a layer in JOSM and Potlatch 2 by using http://www.raggedred.net/tiles/codepoint as the place to get the tiles from.

I have only loaded the HU postcode area so far so, I will need to load areas for other areas if people want them. I do hope no one uses this to enter centroids into OSM, which seems a pointless exercise to me, but it might help people work out post codes for addressing.

Addresses again

2011-01-17T15:58:00.003Z

Some time ago I started adding addresses for my local area. It was tedious so I didn't continue. Then, along came the Ordnance Survey Opendata followed by Bing imagery which together mean I could trace buildings. The OS data is deliberately crude so OS still have something better to sell and the locations are a bit flaky. I have found it is not all that up-to-date in parts too, but still much better than nothing.

The Bing imagery is fairly good, but about nine years old. It is more detailed by one zoom level over Hull though but for most buildings it is good enough here. For the recent additions not on Bing, OS sometimes helps, for others a camera, GPS and guestimates are the best I can do for now. Today I went out locally to gather the addresses of a few streets and ended up talking to a pleasant chap who uses maps and is interested in maps, but had not heard of OSM. I gave him a leaflet and promised to send him more information about getting OSM data onto his GPS.

Adding addresses to buildings seems far less arbitrary and is easier to survey if the buildings are traced and printed to take out to write on. I have so far not attained the level of detail that blackadder has achieved. Part of my, more modest attempts are here.

The one set of data that are a struggle are postcodes. When the OS Opendata was released it included postcode centroids. These are the centre of the area a postcode covers. I ignored it, but now I'm working on visualising these centroids in an editor to see if the postcode for an area can be reliably discerned. That is going well, but rendering the tiles may produce far too much data for my web site to handle, so I'm weighing up the options: limited coverage, dynamic tile generation or find somewhere else to host the tiles. First though I'm going to see if they are useful.

Swords into ploughshare?

2011-01-11T16:29:00.001Z

Things have been a bit quiet on the mapping front for the past few weeks. Short, dark days are frustrating for surveying, the snow that started to fall at the end of November made getting around more of a problem. Then Christmas came along with visiting relatives being far more interesting than being out in the cold.

I have been fiddling with an idea I have for doing some analysis of OSM files. I have decided to make it browser based, but it is early days yet. I may yet struggle with having only a limited amount of disk space available to me online, but it's fun to try new things.

Heading home from a quick trip into town, we passed the Kingfisher pub that has been up for sale for a while. A new sign caught my eye and I was somewhat surprised to see that the pub had been converted to a church. Now that lots of pubs are closing across the country I have been wondering how the buildings will get reused and now I come to think of it turning it into a church is not as strange as I first thought. It is in the middle of the community, it's a reasonable size, it has rooms that the community might use and it has a car park. I just wonder if they will get more customers than the pub did.

Maps of memorials

2010-12-12T12:05:00.001Z

I spent a bit of time looking at the UK National Inventory of War Memorials web site looking for memorials to add to OSM. I realised they need a lot of work to improve their data so I volunteered to help.

I received a set of instructions so I waded in. The job is to update a holding database that will be used to update the main database in time. The holding database has a list of memorials and the idea is to enter the information about people who are mentioned on the memorial, adding as much detail as is available. The holding database has links to data, either .TIF files that hold scanned images or PDFs that hold photgraphs. The scanned images are often hand-written notes from people who have visited the site. This is screaming out for crowd-sourcing. The disconnect between the person who visited and the person who edits is what has caused the errors and omissions that volunteers are trying to solve, but using the same disconnected system.

The first .TIF file I opened had 1667 pages of scanned images, relating to even more memorials and because they are just bitmaps there's no searching or index available. The first PDF I opened had a horrible photo that was barely readable. The memorials I am part-way through has 1200+ names on it, all need amendments.

It is, however, very satisfying being able to correctly name and identify these men (almost exclusively men in WWI) making it possible for people to trace relatives' memorials. I will stick at it.

The coordinator does seem interested in adding a map to their web site. I knocked up an example OSM map based on extracted UK, OSM data using historic=memorial and that quickly showed that differentiating war memorials from all kinds of other memorials is not straightforward. If you are adding a war memorial please add a tag memorial=war_memorial to differentiate it from others such as blue plaques.

I want to encourage them to use an OSM-based map, using their data and then they may release their data for use in OSM generally. I have yet to break it to them that every memorial will need a location and the 6 figure OS grid reference they hold for some of them is nothing like accurate enough since it only ties the memorial down to 10,000 square metres, and that's if it's correct. A crowd-sourcing approach to position the memorials more accurately might be in order.

Shrines, what shrines?

2010-11-22T18:21:00.001Z

Following a project of the week earlier this month to add Memorials we added a few. In order to some idea where there might be war memorials we could survey I googled 'war memorials' and came up with the UK National Inventory of War Memorials which is supported by the Imperial War Museum.

I expected to find a few memorials in Hull, but there were pages and pages of them. Looking closer, many entries were individual memorials attached to grave stones, so I'm ignoring these. Most of what remained were street shrines, which I'd not heard of. The database has a field to enter any reference relating to each entry and most of the Hull ones seem to have come from a single book: HULL STREET SHRINES AND ROLL'S OF HONOUR (sic) by M&M Mann.

I tried to find out more about the book and discovered it was in the local library reference section, which is part of the Hull History Centre. The Hull History Centre is a friendly place, allowing laptops in and providing easy access to their books and map and a complete contrast to the East Yorkshire Treasure House which is plagued by stupid rules (you need a PAT test certificate before you can take a laptop in for example). We went to take a look in the History Centre.

It turned out to be a bit of an odd book. There was no reference information about the book at all, no publisher, no ISBN, no copyright or publishing date and it had been bound by the Hull Library Service. There were indeed a long list of the street shrines in the book, but almost all of it was a series of copies of newspaper cuttings with some that are hard to read being transcribed. These clippings were mostly about the ceremonies to mark the erection of street shrines to commemorate local men who had been killed in the 1914-18 war. There were also articles about how these shrines didn't mention all of the people killed, mostly because they were erected before the end of the war, so more people needed to be added by its end.

One important thing that the web site authors seem to have missed is the introduction. Here, in a bit of a ramble, Malcolm Mann explains that all but six of the shrines no longer exist, for a variety of reasons. He describes the six shrines that do exist, so today we set off to look for them. After searching for four of them in the rain and with the daylight fading fast we gave up. There was no sign of the shrines we looked for. I was expecting to be able to add these to OSM and produce a simple overlay to possibly help the web site. I can show conventional war memorials so maybe that will be useful.

I contacted the web site authors to see if they need any help in our area, but I've not had any response yet. I wonder if they want to include these shrines since they don't exist on the ground and many have not done so for nearly eighty years.

Graveyards and sliding churches

2010-11-16T16:20:00.002Z

A wonderfully crisp and sunny afternoon drew me out into a few local villages looking for more war memorials. The three we found were all in church yards, one being the isolated one at Rowley. Rowley is a very small hamlet, which has a rather nice country house hotel, Rowley Manor surrounded by a farm and a few houses and the church of St Peters. The actual civil parish of Rowley is quite large and takes in the village of Little Weighton. We walked around the perimeter wall to get a trace for it and looked out over the strange lych gate. It is has a path in the church yard to it, but outside of the boundary wall there is just a paddock.

Skidby

Rowley

Walkington

The war memorials are easy to spot because they have the wreaths of poppies on them. I've contacted the UK National Inventory of War Memorials to see if they want to include any mapping on their web site, but I've not had a reply yet.

When I came to enter my traces into the OSM DB, I used JOSM and had a slippy map overlay for the Ordnance Survey OpenData. The area I was looking at shows how badly misaligned some of the OS OpenData overlay is. I wanted to add the churches but the (crude) building outlines in the OS overlay were way off according to my traces. This is a common and consistent problem, both with my current GPS and its predecessor which fell to bits. The overlay always shows objects further south than my traces. I trust the traces more than I trust the overlay's position. In the end I traced a church outline to get the orientation right and slid it to a more reasonable place based on my traces.

Memorials

2010-11-11T16:16:00.001Z

The project of the week has not really rung my bell before, but this week it is to add war memorials, so I added a few local ones (sorry for the quality of the photos, but the weather was bad and the light poor).

Welton

Brough

Brantingham

South Cave

North Ferriby

Plans

2010-11-09T16:18:00.000Z

I heard on the local radio that a large development is being proposed in Brough, a few miles from my home. There was a display in the Brough library about the proposed new homes and commercial area, so I thought I'd go and take a look.

Brough has been very substantially extended over the past ten years. When I was at school there was a very large area of greenhouses given over largely to growing tomatoes and cucumbers and in the summer there were always employment opportunities picking the fruit for anyone who didn't mind being roasted alive in the greenhouses and scratched to bits on the cucumber plants. All of the glasshouses, warehousing and packing sheds have long ago been demolished and a huge new housing estate and a school built there. There have been other new facilities built too, such as a supermarket, health centre and, bucking the national trend, a pub. One of the new facilities is a library and community centre where the plans were on show.

The plans were laid out on display boards, with black and white maps showing Brough and the new roads and building areas sketched over as coloured blocks. I can't reproduce them here for fear of breaking the developer's copyright. The maps were very old OS ones. They showed the market gardens as though they still existed, with the existing, new estate blocked in colour which made it look part of the development. All of the existing, new facilities and some existing roads were drawn in as though they were to be added by the developer. The development that really is to be added is largely on open fields but it is partly on the airfield currently owned and operated by BAe. This is fiercely guarded and is not available for private aircraft to use, so only a few aircraft use it each week. One interesting part of the proposal is to build a new supermarket. Tesco already have expressed an interest in building a supermarket near the A63, not far from this proposed development and the developers are latching on to the hostility to Tesco's plans by saying that their supermarket would be instead of Tesco's planned one.

I have no particular objections to the development, but it is interesting to see how maps are being used to portray a developer's specific agenda and attempt to put them in a good light. As to replacing Tesco's proposal, well Tesco have the cash and planning experience to usually get what they want.

Bridges & stuff

2010-11-04T17:33:00.000Z

When I look at at KeepRight it flags up all sorts of things including where a road crosses a waterway when there's no bridge. There is a small waterway running through Hull called the Beverley and Barmston Drain. I wasn't sure that all of roads that pass over it did so on bridges rather than it simply running through a culvert of some kind, so we went to take a look. The simple answer is there were bridges everywhere, though the pictured one is actually one we already knew about.

As usual when we go out looking for one thing we discover something else. In this case we saw a new industrial estate which is still being completed and a housing estate that is much bigger than it was the last time we checked. The industrial estate didn't have any road names nor a name for the estate, but I expect this to change as the place is finished. The housing estate (pictured) is also still being developed but at least has a road name and also plenty of mud.

The autumn colours in the trees and bushes have been great this year and in spite of a windy day there are still lots of leaves to be seen.

How fast is Autumn

2010-10-29T19:18:00.000+01:00

The roundabout on the A1079 is complete, but the link road from it to the caravan works is not accessible yet. The temporary speed limits have been removed. The new traffic signals on the junctions between the A164 and the A1079 are working and all of this is now in the OSM database.

The leaves are changing colour here, a bit late this year, but they look particularly good. I have heard that spring spreads from the south of England northwards at about walking pace, but does autumn spread south at a similar pace?

Link roads, bugs and limits

2010-09-21T16:22:00.001+01:00

We needed some compost for potting up winter plants and I know that a new link road is being built near to the garden centre, so I thought I'd check it out. I know the road is being built because the A1079 has a frustrating new 30 mph speed limits and speed cameras on it. A roundabout is being added to help the link road join into the main road. The link load is, I think, only going to Swift caravans to help them move their raw materials onto their site and especially move the large mobile homes and caravans they produce off site, directly onto a substantial road and not through Cottingham village. The new roads cuts across North Moor Lane, and would have provided a short cut into Cottingham from the A1079, something the planners want to avoid, so North Moor Lane has been cut in half to prevent this rat-run being created.

Part of the reason I looked at this area is that a newbie had added a huge stretch of 30 mph on the A1079 in response to a Skobbler bug report. The 30 mph limit had already been added, but rather than accept that the editor just added extra 30 mph areas. Bug reporting is a great idea, but it would be nice if people would actually visit the reported area before 'fixing' it. I have sorted it out now, but the new roundabout will still need adding when I can get a GPS trace around it.

A little bit of mapping

2010-09-08T21:38:00.000+01:00

It's been a quiet mapping time, but today after a discussion about some areas of Hull I found myself checking out some of the ten foots off Spring Bank West. A ten foot is the local name for an alley. They run behind rows of houses which are often terraces so these ten foots give access to the back of the houses. The land that fronts onto the ten foot are almost all garages, maybe at one time it would have been a garden. A few of these alleys have been closed to public access with gates. In fact I have no idea of the access status of an ungated ten foot. They tend to be untidy and unkempt and now the wheelie bins just make things worse.

Quiet time filled with toads

2010-08-29T17:35:00.001+01:00

I've not been out gathering new OSM data very much in the past few weeks. I have been running through the OS Locator list of street names in Hull. Following it up on the ground means I have found streets I had missed first time around and ones that have been built since I last visited. All of this improves the quality of the map. I've been doing the same sort of thing in the villages and towns around Hull, but the East Riding of Yorkshire still has a large amount to do to get to the same level of completeness.

I have been experimenting with different ways to place markers on a slippy map. This was prompted by trying to display the locations of some statues of toads placed in and around Hull as part of the celebrations remembering the poet Philip Larkin who died 25 years ago. You can see one example of my efforts here.

I decided to document the process. I'm learning a lot about OpenLayers and that, as you might expect, there are various ways to do it. I am considering how to build a prompted process that helps people create a map on a web site with markers on it and how to help them make the markers respond to actions. It is interesting and in due course, if I get anywhere, I'll post more here. Someone might like to see the documentation at least but some kind of prompt-and-use system could be useful.

Lancing the boil

2010-08-11T12:43:00.001+01:00

SteveC recently wrote a blog entry about the nuisance factor that a small, noisy number of people can cause and how enough is enough. I agree with him that the OSM email lists are almost unusable, being swamped by a few people who seem to want to bring OSM down rather than see it prosper.

One guy, probably using a stupidly obvious pseudonym, comments on almost every email anyone sends, sometimes with more than one reply to the same email and often replies to his own email. You begin to wonder if he has some kind of disorder that needs some help.

Someone else repeats the same mantra over and over. Repeating the same objection and asking the same question over and over doesn't make you insightful, or right and doesn't make your objection or question any more reasonable, it just makes you someone who repeats yourself.

Another guy it seems is a serial project disrupter, having been ejected from Wikipedia. His stock-in-trade seems to be circular arguments backed up with hollow threats to set something up as an alternative to OSM. Sadly he doesn't follow through and remains in OSM to continue to cause trouble.

Some people don't like the proposed change to the new ODbL licence and the accompanying contributor terms. One way of reinforcing their argument against this change is to spread FUD (fear, uncertainty and doubt) about how much of the imported data will have to be removed from OSM because ODbL is not compatible with the imported data. This is, of course, rubbish; why would the sensible, knowledgeable and very hard-working team who have worked on the new licence recommend something that would mean we lose so much? These trouble-makers are free to reject the new licence when they get asked, but they don't want to be Billy Nomates left in an empty space with their data and no prospect of growth, so they want to scare some others into joining them. A pretty despicable tactic if you ask me.

There are other small-time disrupters, people who argue with each other via the email lists, as though a public argument somehow strengthens their point of view. It doesn't of course, it just shows how childish they can be.

The mailing lists are there to ask for help, disseminate information and to discuss ideas and problems. Almost all of this has been swamped by these trolls. Sadly ordinary OSMers get dragged it to this too. Sometimes the mainstream OSMers have tried to engage with the trolls, but that is just what they want. It's like pouring petrol on a fire. The trolls don't back down in the face of reasoned argument or even firm evidence they just go into email overdrive; they would deny the laws of physics just to fill their sad little worlds with their form of entertainment.

Well I say their entertainment has to come to an end. The lists need moderating. When people are deemed to be outside the norms of behaviour they should be privately warned and if they continue they should be suspended from the list for a few days. When they return, if they continue to behave unacceptably they should be asked (or forced) to leave for at least a month. I know this is fraught with difficulties, but OSM is a do-ocracy, so lets just do it and more than that, tell the world we've done it. Lets make it clear that we are about map data, not a home for trolls.

The needs of the many outweigh the needs of the few, these few must act reasonably or expect a reasonable response from the many. If they feel badly treated, let them form their own mailing list or even their own project, and fill that with as much blather as they like.

Crossover

2010-07-31T16:22:00.000+01:00

I write two blogs, one about openstreetmap and one about our allotment. Today I decided to post the same entry in both blogs because I surveyed the plots on our small allotment site. You can see the results here: Allotment map.

More detail is still possible, more sheds, the position of the water butts, and perhaps the plot numbers, but the detail of which crop is where I'll leave alone.

Strange name change

2010-07-07T17:16:00.001+01:00

We've been working through the names in Hull and East Yorks where OSM names differ from the OS Locator names. Today we looked at Mollison Road.

The existing data just showed Mollison Road but the OS Locator claims that the west-most end is Mollison Road West. We took a look and indeed there is a sign which we had missed saying Mollison Road West. At first sight it would make sense that the road might change it's name at the boundary, which has Hull to the East and East Riding of Yorkshire to the west. When I looked closely this didn't add up, the boundary (from OS BoundaryLine data, so probably fairly accurate) would be near the junction with Ulverston Road. Looking at the house numbers this doesn't work. I did a small bit of address gathering and used the buildings from OS StreetView to position them.

If the street name actually changes then the house numbers would have to reflect this, but the house numbers just carry on. There is a small kink in the road that my new GPS shows up nicely, and it seems that if the name really does change then it does so at the kink. This is bonkers. There are no buildings that front onto the tiny part of the road called Mollison Road West, so what is the point of the change of name?

One thing that I have thought about before is that the boundary of Hull has moved a little. I haven't been able to determine if this is true yet, but it would account for this kind of oddity. There is a centre in both Hull and Beverley (one for the UA of Hull and one for the UA of East Yorkshire) with old maps and documents so maybe one rainy day I'll do some more research.

OS road names

2010-06-24T19:28:00.003+01:00

Shaun sent me an email about a Cyclestreets problem report. There is a cycleway that crosses a railway line on a foot bridge with a cycle ramp up the steps. The steps were not in the database, as Shaun suggested. I went out to check it and knock a few OS Locator name issues off. The new GPS gave a much better track than the old one along the cycleway which is under a lot of trees beside a railway embankment, so not only did I add the steps but improved the location of the path too. I added the steps, a bike ramp and a bollard too.

At one end of the cycleway is Perth Street West. OS Locator seems to think that a part of it is called Perth Street. This is clearly nonsense, there is a street called Perth Street to the east of Chanterlands Avenue. It contines to the west of the avenue where it is called Perth Street West. Further west it passes under a railway bridge and, according to OS, becomes Perth Street once again. There are no name plates for this section and no houses either. There are a couple of businesses on the road, including S&R Motors and on the back of their van was the address: Perth Street West, so that's what I'll take.

The OS names of roads become definative, which I don't like. In the village where I live there is a road known as Beech Hill. At one end of the road there is an old sign for Beech Hill, but at the other end there is a new sign for Beech Hill Road. All of the long-standing locals call it Beech Hill, but OS call it Beech Hill Road. Persuading the council that the OS name is wrong is likely to be hard, so I am seeking evidence to establish the long-standing name.

More checks and a correction

2010-06-21T18:34:00.000+01:00

A couple years ago we were checking out streets in the Anlaby Common area and I wrote a blog about it. When the OS Locator data was made easy to use by ITO's tiles I saw that Ordnance Survey were repeating the same stuff that was on Google's Map two years ago, maybe they share the same surveyors. Since it was two years ago I thought I'd check again, as well as some other anomalies. I'm glad I did check, someone has corrected a sign board, though OS still have it wrong.

Two roads run parallel to one another, one is called Plantation Drive and one Plantation Drive West. When we last were there the most easterly road carried the name Plantation Drive West, which I commented about at the time, now the name boards have been swapped. OS still think the most easterly road is Plantation Drive East, which is not what the name board says.

Nearby in Anlaby Common there is a road with a loop called Spring Gardens. OS name all the parts separately as Spring Gardens East, West and South. The signs all say Spring Gardens and the house numbers work for a single street, even though they dot about a bit.

We did find a few small roads that were missing from OSM and a couple of names that were wrong, but there were a few other names that OS had wrong. I'm finding the process very useful to check what we entered years ago and helping find new roads and extentions that we otherwise wouldn't know about.

Comparisons

2010-06-13T12:19:00.000+01:00

I have used the tiles provided by ITO World for a few short sorties to improve the names in OSM. I always use what I find on the ground when I can, but many country roads don't have name boards on display. The Ordnance Survey data that has been released often has names for these roads. I add these from the OS StreetView dataset with a tag source:name=OS_OpenData_StreetView.

I found that I could only look up OS StreetView names and ITO World's tile in an editor. I wanted to see them on a web page. I like the transparent page that sautter.com provide, so I thought I'd do the same kind of page too.

The end result (http://oscompare.raggedred.net) has either a Mapnik layer or Osmarender layer at opacity 1, with either the ITO World tiles or OS StreetView or both over the base layer. The slider changes the opacity of the overlays from 0 to 1 (hidden to fully opaque). I have only tested it on Firefox; comments are, as always, welcome.

New kit and old problems

2010-06-10T19:43:00.001+01:00

I ordered a new Garmin eTrex Vista HCx GPS and it arrived today. My old Garmin is dropping to bits, I've had it for about seven years so it has worked hard. The rubber is coming off which stops the buttons working, the screen sometimes doesn't work well and now it doesn't always download its data without switching off.

The new model is shorter and fatter, with a wider screen. The colour screen seems easy to read. It also beeps which should be better for navigating. The way of moving around the various screens is a little different and I have yet to explore it completely. I don't yet have a spare microSD card - I'll get one tomorrow, so I can't load a map yet.

I took it out for a test run and the quickly became apparent that it has a better receiver chipset. The satellite lock was very quick and the accuracy was showing +/- 8ft to 10ft for the whole test. When the old unit finally got a lock it varied from 19ft to 45ft. Not a scientific test, but I'm happy. Once I got home I could still get a lock inside the house with +/-20ft. I downloaded the track in a moment instead of the few minutes with the old unit.

As to the test route, we went out to check some more of the name anomalies thrown up by the OS Locator data, this time in Beverley. Most of the differences were small roads and especially tracks that were missing. There were a few typing errors and a few that were errors in the OS Locator data. I think the data extract has been changed to include apostrophe differences. There are many examples of inconsistencies with apostrophes on name boards and I found some today, including a small road that had two name boards facing each other, one with an apostrophe and one without. I just accepted the OS Locator version (without).

I used the new GPS track to move a few roads to the seemingly more accurate position, and in the process lined a couple up with the OS Boundary Line data, which is probably right.

New GPS: happy.
Checking apostrophes: no fun.

Wrong road names

2010-06-03T12:38:00.000+01:00

The Ordnance Survey data that has been released is quite a mixed bag. One of the things I have overlooked is OS Locator. This gives a list of roads with a containing rectangle and some location data, such as settlement and county. The coordinates are in OS northings and eastings of course. Itoworld have taken this data and compared it to OSM data in Britain. They created an overlay showing the locations where OSM and OS road names differ, using the OS rectangle to highlight the area. They have also produced a summary of the number of differences in districts, counties and unitary authorities. As usual with Itoworld's work it is useful and accurate but carries the small penalty of taking a couple of days for changes to be reflected.

I took a look at my local area and immediately found errors. This is not a surprise, my work is not being checked on the ground by anyone else and I am as prone to errors as the next man.

When I looked closely it was clear that I couldn't tell if the OS data was wrong or if there were mistakes in the OSM data without checking it on the ground. I selected a dozen or so fairly close to home to check out.

I found a small residential road I had missed, a couple of tracks that were not on our map, one with a clear name plate I had missed. I found a small industrial site with an apparently public road through it that was missing from OSM. There were a few mis-spellings all on my part when I haven't transcribed from the photograph accurately.

Lastly I found two roads where the OS data had a fault. One was easy, OS call a road in Cottingham Middle Dike Lane, the name board shows (and we know from our local knowledge) it is Middledyke Lane. One photo of the name board and a check that there are no other name boards and we were sure.

The second was a bit harder. There is a road called Endike Lane that runs from Hull to Cottingham, at least that's how it looks, but the name board in Cottingham says Endyke Lane and the name boards in Hull say Endike Lane. When I mapped the area I assumed that the name changed at the boundary of the city, but now I know that is not quite true. We found the break point by looking at the house numbers, they number from each end towards the join, so 601 Endike Lane is next door to 42 Endyke Lane and the break must lie between them. This is not as OS describes it, but OSM was wrong too, the boundary is about 200m away. I suspect that at sometime in the past the city boundary did lie where the name changes but has moved since.

To prevent the difference being highlighted again, even though we now know that the OSM data is correct, Peter Miller of Itoworld suggests adding a not:name=Middle Dike Lane. I was unhappy at first about adding data to OSM to show this, but now I accept that it is just metadata like a few other widely used tags, and, unlike any others, it is a negative tag which could be useful elsewhere.

All things considered, this new overlay will improve the quality of OSM, especially in areas where lone mappers are working and I welcome it.

ODbL Deniers

2010-05-16T11:42:00.001+01:00

My weekly copy of New Scientist arrived a couple of days ago. Amongst the usual news and articles there is a series of longer articles about denial. You know the sort of thing: climate change is a myth, there was no Holocaust, HIV doesn't cause AIDS, MMR jabs cause autism, evolution is an atheists' lie, smoking doesn't cause cancer and so the list goes on.

All of these are well known in at least some circles. One at least, Holocaust denial, is illegal in some parts of the world. Some, for example HIV denial, has killed hundreds of thousands of people by denying them treatment.

The very interesting articles describe the similarities between these quite different groups. It outlines the way these denial groups form, spread mis-information, resist and twist the truth and some of the effects they have, including drawing ordinary, sensible people into believing their stories.

As I read these articles, I couldn't help but see the similarities to the process OSM is going through in moving to a different licence. At first there was a lot of discussion about the technicalities, was it the right licence, what might the process be and so on. Once the licence and process had been thrashed out - at great length I might add, the deniers popped up. They had not taken part in the process, they knew nothing about the law behind the licence, they didn't understand the benefits of ODbL or the weakness of the existing CC-BY-SA licence - they just know the change is wrong. So they look for the 'real' reason for change. It must be driven by commercial interests: it must benefit CloudMade or it must be so Google can take over OSM. The wording of the licence is difficult to understand so it must be hiding something and so on and so on.

I know that the OSM licence is not as important as climate change or HIV/AIDS, but it does matter to many people. If you are tempted to grandly delete the bit of the map you have added or send that email accusing someone of hiding commercial bias, ask your yourself this: Am I being sensibly sceptical or stupidly led down a blind alley? Have I studied this or am I reacting without thinking? Do I have real evidence there is a problem or am I making a fool of myself?

I am a natural sceptic. Sceptics question everything, but they let the answers they find lead them on, usually to more questions. Deniers are lead by their agenda and rubbish the parts that don't fit their agenda, however wrong it is, ignoring any contrary evidence. I am a sceptic about ODbL and I think it is the right way to go. CC-BY-SA doesn't fit OSM, it's time to move on. Let's hope the deniers can let go and move on too.

Poles apart

2010-05-13T20:50:00.000+01:00

A couple of short trips out today have helped me to understand the way power lines are represented by the Ordnance Survey VectorMap shape files. The shape file gives no clues about the power lines, they are all labelled the same, but there are two types of power line represented.

The first type is lower voltage that is supported by two wooden poles. It does seem that the nodes do represent the actual poles, at least most of the time.

The first photo shows where two lines join with a bit of a crossover and this to be represented by the ways shown in JOSM. The crossover seems to be to relieve the strain in the cables. I have followed a couple of lines where they were accessible and checked the poles and they seem to be where the nodes are. This is very far from exhaustive, so I'm only going to add lines that I have checked. I also followed a short bit of power line on a single pole and that turned out not to be part of the OS data set.

The second kind of power lines have steel pylons. I have checked a couple of lines and the gaps in the ways do seem to be the position of the pylons. I think there are different sizes of pylons. If the gap in the way is proportional to the size of the pylon it might be possible to deduce the type of power line, but again I haven't been able to confirm this yet.

The biggest problem I can see is that it will be a fiddly job to join each short section together with the node in the middle for the tower. I'll see if I can sort out a program to help out ...

More OS data

2010-05-12T22:16:00.002+01:00

I have written up notes about using OS shape files in the wiki here. I hope it's useful for anyone else who wants to use them.

I thought I'd take a look at a few of the other features that might be useful from the VectorMap data set. One thing that I glanced at before was the Settlement_Line. It seems to be electricity transmission lines, at least all the ones I've seen so far only contain this. Loading these power lines could be useful, but in OSM we mark the pylons as well as the lines. 50k OS maps mark the lines but they don't show the locations of the pylons, so you can only be sure there is one at corners and junctions, so I thought these might be the same.

I did the usual re-projection of a shape file for one of the 10x10 km areas close to home. I then modified a python script to extract all of the polylines in a shape file and ran it. When I loaded the osm file in JOSM I realised there are at least two types of power line. One way is in longish sections which are not straight. There is also another type; this is made of single sections between two nodes with a gap of more than ten metres between each section.

I think these are different types of power line. The continuous lines are lower voltage lines, with the gaps marking where the pylons are in a high voltage line. I need to go and look at the lines I have identified locally and see what I find. If I'm right it will take more work to join the sections of line together, since OSM only uses a single node to mark a pylon. It doesn't make the location of power poles on the low voltage clear yet either.

Power lines, especially high voltage power lines, can run large distances from power stations to towns and cities and the 10km squares that the data is supplied in breaks up the lines into annoying sections too.

Sign of the times

2010-05-06T10:45:00.002+01:00

My local council (East Riding of Yorkshire) have a rolling programme of improvements that they apply to all of the 280 or so villages in the county. It's called Street Scene and it is a way of fixing the small jobs, like small road repairs, fixing or replacing signs, bins, fences and anything else that the council is responsible for. Like all council schemes it starts out as a good idea then descends into a money-wasting exercise which is basically budget led. In the end jobs get done because there is money that needs to be spent by a certain time or lost and not because the job really needed doing.

All of the street name signs in the village were 'reviewed' and ones that were shabby were replaced. The sign pictured is a new replacement. The sign faces a T junction on one of the main routes into the village. It had an arrow pointing left for West End and an arrow pointing right for Main Street, which is wrong. The break between these two roads is not at this junction and some of West End lies to the right.

I emailed the council explaining that the new sign was misleading, they refused to fix it saying that it was the same as the old sign (not true) and that it was not wrong. I gave up, knowing the real reason was that the money had run out.

Some months later I bumped into Geoff, our local parish council chairman, near the sign. I mentioned that it was wrong; after some thought he agreed and I suggested that all that needed to happen was that the incorrect arrow be painted out. Today I noticed that that is exactly what has happened. I don't know if Geoff did it, an expensive council workman did it or someone else did it who had the same idea as me and had some white enamel paint to hand, but whoever painted out the arrow, thank you.

Using the VectorMap

2010-05-05T19:56:00.001+01:00

I decided to use some of the OS VectorMap data. The stuff that makes the most sense is the natural features: water and woodland. There are some fish farms near Driffield alongside the river Hull that have loads of little lakes and streams, so that looked like a simple target that would add some value.

Having re-projected the VectorMap shape file of the area, I selected a group of lakes and ponds in the shape file using QGIS and saved them as a small shape file. Next a little python scrip was thrown together to extract all of the polygons and change them into an osm file to import into JOSM.

There were a few things to change, the river Hull needed to be sorted into riverbanks, some of the small streams needed to be joined up properly, but really it was very easy, and much better than tracing the ponds.

OS VectorMap District

2010-05-02T12:30:00.000+01:00

Using the experience gained with the OS BoundaryLine data I thought I'd take a look at the VectorMap District data that the Ordnance Survey have just released. It is organised into chunks based, not surprisingly, on the OS grid. The grid has 100km squares labelled with letters (you can give a grid ref without the letters, but the VectorMap uses the letters). Within each square there is a simple grid system with two parts, known as northings and eastings. The VectorMap uses a single digit of each to define a 10km square. When you have worked out which square you want and opened the folder for that square there is a variety of shape files in it. My village happens to not only fall across two 10km squares but two 100km squares, so I need SE92 and TA02 to cover the whole village.

The shape files cover a range of features: administrative boundaries, community services, heights, natural features by area and line, railway lines and points, roads as lines, settlements by area and line, text and tidal boundaries. I haven't investigated any of these exhaustively and some only cursorily and my findings so far are mixed.

The administrative boundaries seem to be the some of the same ones in the BoundaryLine dataset, but with the disadvantage that they are spread over many 10km tiles, so using the BoundaryLine ones is easier and has more boundary types.

Community services seem to be schools, I haven't found anything else. I might have expected all public buildings, for example libraries, which get highlighted on the StreetView rasters, but not as far as I can see. They are only shown as a point and with no name or other description.

Heights seem to be spot heights. The feature description is 'Heighted Point', which is neither descriptive nor English.

The natural features is interesting. It seems to contain woodland and water features, both seem useful. It also contains 'custom landform' which I still haven't identified yet. On tidal waters it seems to show the low-tide level, i.e. areas that always have water cover.

Railway lines shows the railway lines! It seems to show at least some sidings and multiple track sections. Some are labelled as multi track railway, some as single track railway.

Railway points shows stations with their names.

Road_line has the roads in the 10km square. They are listed with their type (A road, B road, Minor road, Local street - there may others elsewhere). The A and B roads have numbers, some roads have names, but most do not, including residential and minor roads, which would be the most useful. When I looked closely at the Road_line detail it was clear that some newer roads were missing, including a local estate built about ten years old. Also most private roads are missing too. In contrast, a small estate completed only about 18 months ago is in the Roads_line data. I would not trust this to be complete, and the lack of names limits its value.

Settlements by area seems to attempt to show where buildings are. It is showing this by blocking in areas, but these seem very arbituary. There are gaps between the blocks that don't really make much sense. It is more up-to-date than the Road_line data, since the estates that are missing from the Road_lines are present in the Settlement_area, including leaving the space for the missing roads. It does distinguish some building types, such as glasshouses.

Settlement_line seem to show electricity transmission lines, though not any more detail like their voltage, nor the position of the posts or towers.

Text is a list of points with the text that should be written there. The font size and display angle is listed too. The list of named items includes, places, waterway names, farms, bridges, in fact all sorts of things which may be useful to see on a map. Without the context of the object it seems useless to me.

Tidal_boundaries show the high and low water lines in some detail. I need to compare this to the high water mark in the BoundaryLine data, which I think is somewhat out-of-date. I'll post those results later.

Over all there is some interesting data in here, but, like the rest of the OS data, it is a mixed bag. I think OS have released a lot of data in a fragmented way that makes it hard to use without a lot of work to glue it all together. OSM seems like the perfect platform to put the useful data into, but only with quite some effort and, as always, best tempered with local knowledge.

Getting boundaries right

2010-04-25T21:55:00.000+01:00

I've got to grips with the boundary data that the Ordnance Survey released earlier this month. The data was in shape files and, with the help of OSM::SK53, I have extracted OSM style data from them. Shape files are a twenty-year-old format that can include a projection file (*.prj). This was where the problem lay that stopped me using the data before. With Jerry's help the projection file was altered and then the process of changing the projection OS use to the one OSM uses was easy.

If you are thinking of using OS shape files be warned: don't trust their *.prj files - they are incomplete.

Once the shape files were in the OSM projection I could then extract polygons or polylines from them. I created a python script that will extract a named parish boundary polygons or numbered polylines that make up the coastline. I spent a few mind-numbing hours loading each of the parishes that fall on the outside edge of the county of the East Riding of Yorkshire. I created a relation for each parish, and deleted each of the sections of ways that were duplicated between parishes. The outer edges of each parish also marked the edge of the county too, so the relations for the county and the region has improved too.

I have also updated the coastline ways from the Boundary Line data set from OS. I managed to leave them broken over night, as OSM::PA94 realised and helped to fix. The coastline is not often updated - it's not part of the normal rendering process for Mapnik, so I'll have to wait to see what Mapnik makes of it.

I have noticed a few things as part of this. The boundaries sometimes follow a stream or river, but sometimes the boundary leaves the river briefly, probably because the river has moved, but the boundary hasn't. The boundaries do not follow the centre line of roads. They clearly lie at one side or the other and at certain points you can see where the boundary jinks across to the other side.

Lastly I have to say the match between the boundaries and the surveyed areas is very close and I'm very comfortable in using the OS data for boundaries, especially because there is no better way to survey this data on the ground.

I will write up the detail of the steps involved if there is any interest.

OS Data part 3

2010-04-18T22:22:00.000+01:00

The OS data is correct. I have checked a few points in polygons in the shp file in the OS projection and they are the same as a paper map, so somehow the transformation from OS to OSM is translating the result.

As an example a point on the transformed shp file is 53.76098, -0.48939 should be 53.76129, -0.49106. As a bodge I'll add the translation to the OSM output and then test a few more places to see if the translation is consistent across the country.

OS Data part 2

2010-04-18T21:45:00.000+01:00

I've checked the transformation from the OS projection to the OSM projection and it seems to be correct. The resulting boundary is the right shape and size, but it is shifted to the east. I'm going to check out exactly how much - it would be possible to correct it during the creation of the OSM file.

Why would this data be translated? The transformation could be wrong, the OS data could be wrong, the existing OSM data that I'm comparing it to could be wrong or something else. I have tried the transformation with two separate programs and they both produce the same results. The existing OS data has been gathered by various means and is likely to be mostly right. There is a chance that the OS has an error, I wonder if anyone else has looked at it yet.

If the OS data is OK, then what else have I missed?

Ordnance survey boundaries

2010-04-18T19:23:00.000+01:00

The UK Ordnance Survey has generously released some of its data for unlimited use. One of the data sets is about boundaries and included in it are parish boundaries. Boundaries are not painted on the ground so adding them to OSM is hard. Some people have added some parish boundaries, or bits of them, from the out-of-copyright NPE maps from OS, but a lot has changed in over sixty years.

The OS boundary data comes in the form of ESRI: shape files, about 179MB to make up the parish boundaries. I loaded it in QGIS to take a look at it - there where about 14,000 polygons. Dealing with this is not going to be a small task.

I dug about T'Internet to work out how shape files work and after a bit of work I've extracted a list of the polygons in the shape file, then a method to create an OSM file for each polygon suitable for loading into JOSM.

I loaded the polygon for my village and at first sight it looks good, but when I compared it to a real OS map, the parish boundary doesn't quite match - I've not transformed the shape file from its original OS projection to the OSM projection correctly.

This is not the only problem of course. If I load a single parish boundary that's fairly easy. If I want to load an adjacent boundary some of the nodes need to be shared nodes along parts of the boundary. In addition the parish boundaries will share nodes with the county boundaries too. There are district boundaries available too, so these will also share nodes. On top of this there is the problem of dealing with the existing data that people have already loaded which might need to be merged, deleted or tagged as an historic boundary. This alone makes it important that each boundary is processed by someone who can make decisions about what to merge etc.

I'm going to sort out the projection issue, then import a single boundary via JOSM and see what that looks like. If that goes well I'll import an adjacent boundary and see what it takes to merge the shared nodes.

If I can make this work well, I'll write up a process and consider how to offer parish boundary files to other people for them to import in their local area, but supplying 14,000 files might be too big a task. Then there are the other boundaries types too ...

Ringtone ?

2010-03-30T16:53:00.000+01:00

We made a short trip out to Howden, so on the way we took a second look at Eastrington, Or should that be East Ringtone?

These second visits always yield extra information, so they are worthwhile. In Howden I noticed a large school that we had somehow missed. We took loads of photos (it's the Easter break so no indignant people complaining about taking photos near a school) and used what evidence we could find to estimate the boundary of the school.

Smooth

2010-03-22T19:12:00.000Z

We went to Long Riston today on a wet and breezy day. On the way, one thing I noticed was a smooth new road. Stavely road is used as a part of a short cut between Hedon Road and Holderness Road. It used to be a spine crushing route full of pot holes and badly filled pot holes, with some ridges in the concrete slabs adding to the problem. The new surface is smooth and flat. It's not the usual lick of tar and stones, but a proper new layer of tarmac.

The Ordnance Survey recently asked for comments on the idea of releasing some of its data for public use. The process ended last week. Today, No. 10 announced that a substantial amount of OS data will be released for use without restriction. Details will follow in a week or so. So what was the consultation period for? Government processes take months not days to evaluate things, so it is not possible for a standard assessment process (if one really exists) to have been applied to the submissions, many of which came towards the end of the consultation period. I can only conclude that what ever data is released must have been decided some time ago. If that is the case, then why the consultation period?

Of course the imminent election may have led to short cuts in the process - I just hope that the route ahead will be a smooth as the new Stavely Road.

If the OS data is useful (that might be a big 'if') and freely available I wonder how it will be used in OSM. It largely depends on how it is released. If it is raster data then the process of tracing from a map already exists and is already well understood. It is also suited to our crowd sourced model - lots of people each add a bit and we get a great database.

If it is vector data (which I think is more likely) then we will need to process the vector data into a form that it can be used in OSM, probably not a difficult job given the expertise we have. Then we just need to decide how to use it ...

Numbers and canal

2010-03-09T17:36:00.001Z

Another foray into Driffield has given us another chunk of the town with a decent basic cover. One of the areas I wanted to look at was the canal head. OSM's resident canal expert sent me some information on the refurbishment of the Driffield Navigation. Today we only drove past, but another day I want to map it in detail.

The rest of the residential area we checked out was fairly straightforward. The changeovers between some road names were a little unclear until we looked at the house numbers, especially The Mount, Southfield Road and Southfield Close. Checking house numbers is something I have used many times to be sure if a street name has changed and today it worked well.

Tile viewer

2010-03-07T21:21:00.000Z

Now that I have the beginnings of a renderer, it needs a GUI. Well, that's what I told myself. Since the the path to a renderer has really been a journey towards understanding Java, I need to explore more of Java and its classes. One of the options Java gives is a graphical user interface - Swing. I have had a fiddle with Swing using NetBeans and I'm pleasantly surprised how easy it has been. I am very familiar with GUI programming in other languages and it seems that Java follows a similar route. I now have a rudimentary viewer for a tile, though rendering that tile nicely is still a long way off.

Pubs and coast

2010-03-01T09:39:00.001Z

A wet sunday afternoon saw us in Driffield. The satellite reception was awful most of the time, but we got lots of photos which help to make up for it. The rivers and becks around are very full and the ground is sodden, so a few days of dry weather would be useful. All over the country pubs are closing, but not, it seems, in Driffield. There were loads dotted around the market place and only one that looked closed down. There's still quite a lot of the town to complete - I hope the satellite cover is better next time we go there, it would be nice to be able to predict good coverage for an area ...

I've been working on rendering coastlines - I think I've finally sorted it out. Drawing coastlines made up of ways that are not closed polygons, when there are many possibilities of how they can be arranged, and including islands and lakes has been tough. It has forced me to revisit some long forgotten maths, including calculating cross products of line segments to decide if a closed way turns clockwise or anti-clockwise.

These two pictures show tiles with fairly complex coastlines drawn accurately - the Pacmen are lakes and islands. Making test data with JOSM has been very useful - testing with live data never gives you all the possible circumstances, but it will give me volume data tests later. Text placement next I think.

Coastlines again

2010-02-23T21:06:00.000Z

I really am an untidy person. Without the pressure from my better half I would live under a huge pile of stuff that should be in drawers or boxes or whatever. Code is, however, a different world and it has to be tidy.

I've just finished tidying up the coastline routines on my renderer. It is much better now, distilled into sensible classes and built around a simple state engine. There are a few tasks still to do but they are documented and have slots to put them in. There is a lot of testing to do yet too. I have been creating test .osm files that cover as many eventualities as needed, which for coastlines is more than I expected.

Now the tidy itch has been scratched I really can move on.

Crick in the neck

2010-02-23T17:17:00.001Z

A cold gray day didn't tempt me out, except in the car. We went to take a look at the villages to the east of Hull, and check a few bus stops against the NaPTAN import at the same time.

The quality of signing was very poor, only one stop had the NaPTAN code on it and a few stops with shelters had no signs at all - I guess these are working stops. One of the stops had a sign we nearly missed, perched on top of a pole, level with the first floor windows, probably about five metres up.

We have checked nearly 50% of the bus stops in East Yorkshire, but those that remain are getting further from home.

Coastlines

2010-02-21T19:27:00.000Z

I've been looking at how to render my own maps. It started as an exercise in learning Java but has become a tussle with coastlines. In OSM the coastlines are stored as a collection of ways with natural=coastline tags. They can have other tags too of course. These ways should join up. The big issue is that they don't individually form a polygon which can be filled to make up the sea.

My renderer-to-be is working on a .osm file. Depending on where that file covers it might contain coastline ways and they might be complex. It has proved harder than I thought create a filled-in coastline. Drawing the ways is very straightforward. I found a flood-fill routine (Java doesn't seem to have one built in) and tried to use it to fill from the way to the edges. This is harder than I expected because the twists and turns of coastlines.

I then decided to work differently and create polygons (which Java is good at filling) that are made up from the way and the edges of the canvas to draw on. Because the land is always on the left of a coastline way, I can work out which part to fill. Finally this seems to work.

There is more work to do to improve the handling of multiple, unconnected sections of coastline on a map, such as drawing a section of a peninsular or a section of an estuary. There is still an issue of a closed way: is it an island or a lake (some lakes are drawn with coastline rather than natural=water). Clockwise closed ways are lakes and anti-clockwise closed ways are islands. I want to review the way I manage the classes around this too.

I'm going to move on to other stuff for now and return to coastlines later. Next is a style sheet. I've looked at MapCSS and I've looked at Maperitive's style sheet. I think I prefer the latter. It seems to use a system of identifying what an object is and then how to draw it. This allows similar things to be treated similarly: amenity=graveyard and landuse=cemetery could both be identified as a graveyard and drawn in the same way. This is exactly how I expected to work. Maperitive also has built in support for zoom levels, which don't have to be integer values. So that looks the next task.

I don't know how far I'll get before the weather improves. Then there will be more draws to be outside: walking, cycling, mapping, working the allotment etc. We have managed to work on Driffield. There's also the town of Hornsea and about 40+ more villages to complete in East Yorkshire. Completing all of the roads and villages in the county is high on my list for this year.

Driffield and renders

2010-02-14T17:25:00.002Z

Today we went out to look at the town of Driffield. It's a market town which is advertised as the Capital to the Wolds, though I'd expect it to be in the Wolds to be the capital, not perched outside the edge. It went well enough, almost all of what we mapped was new. There is a substantial chunk of the town which looks mapped at first sight, but I suspect will need going over again. The roads look traced from NPE, they have tags like highway=unclassified when I think they are residential and they have no names. So, we'll check them out on the ground and get the real picture.

I have also added some streams from NPE. I saw the stream flowing under the road bridge and the only real way to add it was from the old maps. Yahoo is very low-res and there's a cloud in the way.

Driffield will take many visits to complete, but it should be a pleasant place to wander around.

I have been experimenting with rendering my own maps lately. I started to look at Java 6 (1.6?) over the winter and now it's turned into a project to render maps. I have started with a tile-based drawing because it is easy to compare it with a Mapnik-rendered tile. In due course I do want to render a map that is a single png file of a chosen resolution and of a chosen area. It's mainly an exercise to force me to get results from writing Java and, as yet, it is a command-line program. I've looked at Swing a bit and it could form the GUI for selecting the area to map.

The latest, almost solved, problem is how to draw the coastline. They are drawn as open-ended ways so the sea is not a closed polygon to simply draw filled. I have resorted to creating a flood-fill routine (based on the work of others of course) to flood-fill the sea once the coast is drawn. It may also be useful with drawing multipolygons too.

The next issue to address is how to manage the style sheet. I've looked at MapCSS. It's interesting, flexible and extendable. It would make a degree of compatibility with Richard's work too. Parsing MapCSS looks to be a real problem to me. I could just create an XML format for the style sheet, but who in their right mind wants to hand-edit an XML style sheet to get a map to render? So I'm still thinking. Any ideas would be welcome.

Mid winter mapping

2010-01-28T16:31:00.002Z

This time of year really feels like mid winter. The days are still short, sunset is about 4:30, and every bit of colour seems to have been stripped from the countryside. Even the grass seems dull and gray. There are no hints of new growth, flowers or blossom yet.

After a long break from mapping we set off to take a look at Beverley, a pleasant market town in East Yorkshire. We were looking for detail to add to OSM really - most of the roads and other significant stuff was added some time ago. After a little wander around we went home so I could add what we had found.

On the way home, in fact just a few hundred metres from home, we came across a flock of fieldfares. They have flown here from Scandinavia to escape their winter.

After I'd finished updating OSM I took a look at Google maps, which I rarely do. I was quite surprised how it has changed, especially adding lots of POIs and businesses. As usual their quality control is poor, with the impressive building of St Mary's Church shown in completely the wrong place. It has been there since the 14th century, so they've had plenty of time to find it. St Mary's is not the biggest church in the town, that has to be Beverley Minster and that's not even named on Google's map.

During my enforced stay at home I've been teaching myself Java. I looked at it years ago and quickly turned away from it, but now it seems more mature and useful. The Netbeans IDE seems useful too. I've written some OSM stuff as a set of tasks and I'm going to look at some more too. My main gripe is the lack of properties in objects. The fields can be exposed as public, with no control over their use, or hidden as private and then only accessed with set or get methods. I want to see fields encapsulated as properties with setter and getter routines used transparently to validate updates and manage related properties. Always calling obj.getprop() and obj.setprop(x) seems very crude. I could be missing something of course, so add a comment if I am, but no consultancy or training fees are avaiable I'm afraid. I still have to get to grips with the huge library of available classes, but that's what long, dark evenings are for.

Snow, what snow.

2010-01-11T18:45:00.001Z

All sorts of stuff seemed to get in the way of getting out and gathering some map data. Most recently the unusual amount of snow has kept us close to home. Overnight the thaw set in and the roads were largely passable. I decided not to set off deep into the rural parts of East Yorkshire so we took a look at the bus stops in Bilton, which is on the edge of Hull.

The drive through Hull was a surprise - there was almost no snow, even in places that would not have been cleared. On Friday the local news reported that traffic in the city had been badly delayed - a short journey took a few hours. Today that was hard to believe.

When we got to Bilton the bus stops were quite straight-forward to find. Only one (pictured) had the NaPTAN code on the sign, but that is not unusual. There was a stretch of road works on the road towards Preston and three stops were wrapped up in that. They looked as though they had been removed some time ago. If they were in use there would have been temporary stops beyond the road works, which we did not see.

The short days restrict photography at the moment so the forays are short and fairly local.

Experimental photograph

2010-01-07T15:51:00.000Z

My mapping has been almost at a halt for a few weeks now, what with Christmas, snow and other stuff. A few other distractions have crept in; I tried to take a photo of a bird in the garden using a mobile phone camera through the optics of binoculars, with some success. Well actually I didn't photograph the bird, a redwing, but the branches of the tree came out well.

I have tried this sort of thing before using a compact digital camera to take pictures through a telescope, indeed amongst bird watchers it has been popular for some years and a new portmanteau word sprang up: digiscoping. I thought I'd try through a scope to see how easy it is.

With the telescope on a tripod it leaves your hands free to hold the phone. The position of the camera in relation to the eye piece is the critical thing. It needs to be just the right distance away to maximise the extent of the image used, too close and the image is a small circle surronded by a huge black border, too far away and the image is impossible to keep still. I'm talking a millimetre or two either way. It's also important to hold the phone perpendicular to the line of sight through the telescope to avoid unbalanced focus.

It worked but not that well. I snapped a couple of shots of a tree about 50m away, not the most inspiring subject, but its twigs show a good spread to check the focus, which is far from perfect. The horizontal lines are telephone cables.

My findings: buy a good telephoto lens for your SLR.

Arguments

2009-12-13T12:11:00.002Z

Monty Python had it right. Some people really would pay to sit in a room to have an argument. The modern day equivalent of the Python's Argument Room would be a chat room, a blog comments list or a mailing list and people don't even have to pay. Here they can provoke others into spurious, circular arguments that get nowhere and some people clearly just love it as a sport.

The OSM-talk mailing list has become the pitch for this sport. I'd like to see a bit of proactive effort by the administrators. When someone is repeating the same old stuff, over and over or when their posts exceed a certain percentage of the total posts, the administrator should ask them, off-list, to be a bit more restrained. If that doesn't work then a public naming followed by a suspension or ban might be in order. Let's get the list back for useful exchanges and banish the trolls.

Ploughing

2009-12-11T15:52:00.006Z

We went out today to take a look at a site in the Yorkshire Wolds where there is some ridge and furrow marks in a field. There are a few places in East Yorkshire like this, though they tend not to be quite as prominent as areas in the Midlands. The sun was quite low in the sky and the shadows cast across the field were just about good enough to see the furrows.

These marks were made by ploughs that couldn't turn its face round like modern ploughs do. All of the earth that was turned over by ploughing over very many years formed a bank in one part and a trough in another. The only ones that survive today are where the land has only been used for grazing since medieval ploughing stopped and not touched with a modern plough, so most of these marks are hundreds of years old, some over a thousand years old.

I could put it on the OSM map (I'd have to invent a tag but so what), but I choose not to because such archaeological sites get pillaged by treasure hunters with metal detectors so I don't want to encourage them.

History Centre

2009-12-03T15:51:00.004Z

While we were in Hull today we took a look at the new History Centre. It's not open yet, not until the new year but it looks impressive from the outside. All of the city's paper archives are going to be stored here, a few from when the city was first awarded its charter in 1299 when it changed its name from Wyke upon Hull to King's Town upon Hull. The city is very low lying, with some of the city centre below high water mark. According to my OS map for the city they have chosen the highest part of the city centre to build this museum, it lies about 4 metres above mean sea level. The normal spring tide range in the marina is 6.4m so this doesn't seem very safe to me with only 80cm to spare. It was previously housed in the Central Library only 350m away, so it's no worse off. I expect that the curators took flooding into account.

Years ago I did some work with a warehousing company in the Netherlands. During due diligence we wanted to know about flood risk in such a low lying country and when we discovered that their whole site was eight metres above sea level, they were so proud of it that they put a brass plaque up in their reception to that effect.

We have been checking a few bus stops in East Yorkshire recently. One thing I find odd is the idea of a CUS stop. This seems to be a customary stop, where buses might stop. The key thing seems to be that there is no bus stop sign at a CUS stop. We were checking such a stop when a bus rolled up and dropped off a passenger. That confirmed that there was a stop there, but I find this odd. Why have a stop that's deliberately not marked with a sign? No one benefits from this. I just don't get it.

Names, power and prisons

2009-11-27T20:51:00.010Z

We went out today, partly for a ride out on a lovely day, and partly to check some stuff for OSM. Like a lot of sorties to gather map data, it just leads to more detailed uncertainty later. I checked a few bus stops in North Cave, but when I got home I realised that the street name on the NaPTAN data did not match the name on the street in OSM. I can't resolve the problem at home, so we need to go out and check again.

On the way we had a view over the Vale of York from the edge of the Wolds. In the distance is the huge power station of Drax, making about 7% of the electricity of Britain, using coal imported from Australia, with vastly wasteful steam rising from the cooling towers to form the biggest cloud in the sky today. Later in the day there was an item on the TV about electric cars, but while the power to charge its battery comes from places like this and is delivered through the national grid with all of its losses, they make no sense at all.

Later we checked out the approach road to the prison at Everthorpe, officially HMP Wolds. It seemed a bit odd driving towards the prison, but it seems to be a public road, though I think we were on several CCTV cameras. We took a turn around the roundabout at the end and left as quickly as we could without seeming to hurry. I don't think it would have gone down well to take photos.

Slowest

2009-11-24T11:01:00.004Z

We went out yesterday, gathering some details as we went, including some missing speed limits. On Priory Road we came across the oldest, slowest tractor I think I've ever seen on the road. It looked unsteady and probably unroadworthy. It was only managing about 5mph, off the bottom of my speedometer, so it wasn't causing much of an obstruction as getting past was very easy. We finished our job and headed back along Priory Road, only to find the thing still plodding along. It looked like more of a museum piece than a working tractor but it did look to be going a bit faster, maybe 8mph. A decent part of its load was now strewn along the road.

NaPTAN in East Yorkshire

2009-11-19T20:10:00.007Z

Edgemaster has loaded the NaPTAN data for East Yorkshire, so there's another 1622 stops to check. There's been quite a lot of muttering about data imports, much of which I agree with. I think imports should be treated as the start of a process to improve the data they bring and imports need managing by people local to the area the import covers. Imports can bring valuable data in their own right, and the process of checking them certainly gathers extra POIs and extra tracks for lightly covered areas. A few local mappers are checking their local stops.

We've been out locally checking the quality of the data. Compared to Hull's stops the ones in east Yorkshire seem to be much more accurately positioned. The biggest problem so far is that the Atco code is missing from many of the stop signs.

I know that the East Riding of Yorkshire council have some plans for assisting passengers with some new information system and I think they need to have the code on every stop so people know where they are. I hope they will benefit from our findings.

Today we checked the stops in Welton, Brough and Elloughton. There are few shelters and they are mostly old brick built ones, but a couple have been improved.

Last stop in Hull

2009-11-10T15:29:00.003Z

We've just checked the last bus stop in Hull. The process has been hard work at times, but there's more reward to it than it might seem. We've added a lot of detail that had otherwise been missed. Today we set off to check the last four stops that are tangled up in a substantial rebuild of James Reckitt Avenue. Checking the four stops took a few minutes, and we found a church that had been overlooked. There is a push to import data from various sources - I don't think it should be imported unless there is an accompanying checking process. That checking process must be done on the ground not from your armchair. It must, therefore be undertaken by someone local to the import process. National imports must be broken up into chunks that are managed locally. This is the way NaPTAN data has been loaded, though not every stop has been checked yet.

So, some stats:
NaPTAN had 1299 stops listed, we found 9 extra ones, total: 1308

91 stops (7%) were missing
66 stops (5%) were substantially moved
139 stops (11%) had the wrong bearing
51 stops (4%) had no ATCO code on the sign (there were 39 more in the new transport interchange, but these are electronic boards that don't really need labelling. School bus stops also had no codes).
10 stops (0.7%) had the wrong code (after investigation)

I have yet to send the last batch of data to the Transport Team in Hull City Council, let's see what response I get.

Awkward

2009-11-02T18:17:00.004Z

The bus stops that have been loaded from the NaPTAN data are not all accurate, so we've been checking the ones loaded in Hull. Some can be checked from a car which helps cover the ground quickly, but traffic can make it difficult. When a bus stop has a bus in it, stopping there to get photos and a good fix is not easy, but when there's a police car in the layby and a bus stopped next to it, then maybe that stop needs to be checked later.

NOVAM & Vista

2009-10-28T15:18:00.002Z

I've been checking bus stop data that was loaded from the National Public Transport Access Node (NaPTAN) database, donated by the Department for Transport. Christoph Böhme has created a viewer called NOVAM and kindly added a colour scheme based on my choice. You can see it here. I wanted to try it with IE since the people in council Transport Offices will probably use IE.

My laptop came with Vista. I loaded a dual boot Ubuntu which I use all the time. To try out IE I restarted the machine in Vista. I haven't used Vista for weeks, so the virus checker had expired. I decided to delete it and add a free one. Whilst doing this the Windows update process had downloaded umpteen updates so I foolishly agreed to install them. I had installed the Thunderbird profile on a folder on the Windows NTFS drive so I could use email on both Windows and Ubuntu and see the same messages etc. That was my downfall. At some point windows must have hibernated, I didn't realise, restarted the PC in Ubuntu, did some stuff in Thunderbird, then restarted in Vista. Vista now recovered my running email to the way it had been and threw away my newly downloaded emails.

Now I haven't lost much, but it has just been the last straw. I hate hibernation, but it doesn't seem easy to turn off in Vista - part of the Micro$oft policy of we know best, we'll take your PC that you paid your money for and make it work our way even if you don't like it. So Vista is no more and how good does that feel.

I do have another PC (well a few actually) and there is XP on one of them, so I'm not without access to Windows, so now I can try NOVAM in IE which I didn't actually get around to in Vista in the end anyway. I hope it works.

Wilberfoss

2009-10-19T17:52:00.003+01:00

We had a break from bus stops and went back to village mapping. The village of Wilberfoss is alongside the A1079, which is not my favourite road, but once you're in the village the busy road between Hull and York just disappears. We followed the twists and turns of the older part of the village with its extensions into newer stuff. There's a beck, a pub, a school, a church and it's a pleasant place. The beck is quite small but there's a chunky bridge over it which seems way too big. I traced the beck from NPE, I tried the new 1:25000 maps but they didn't load after a few minutes so I gave up. This internet connection is variable, so it might have been us, but NPE loaded almost instantly.

Council update

2009-10-14T18:54:00.002+01:00

I've sent another batch of bus stop checks in Hull to the city council. I'm a bit disappointed about the lack of feedback from the transport team. The bus stop data is, however, much better than it was, with stops better positioned, missing stops removed and extra stops added. Some of the NaPTAN fields have mistakes. I have sent the issues to the council transport team so they can update the NaPTAN data at source. I haven't changed any of the real NaPTAN fields because I expect this might be reloaded from another NaPTAN update and then any fields I change would be overwritten.

I am looking forward to finishing this and then moving on.

Stops again

2009-10-07T16:54:00.002+01:00

We went out to verify some more bus stops in Hull. The stops have been loaded from the NaPTAN import and have generally been quite good. They are labelled in a straight-forward way and generally their positions have been pretty good. The NaPTAN data includes a bearing showing the direction a bus will leave the stop, in Hull's case this is the 8 cardinal points N, NE, E etc. These bearings are the biggest single error, and it's easy spot. I make a note of such errors to send to a chap in the council so, hopefully, he will update the NaPTAN data from what we find.

We drove up and down Spring Bank today. Driving looking for stops is tricky, but in the slow moving traffic today it was very easy, we stopped alongside most of the stops in traffic which was heavier than normal because of road works. It's generally too far to walk between most stops - it would take too long - but one problem with driving, rather than cycling, is that you get hung up on buses. If I stop at a bus stop for Jean to photograph the sign etc., but a bus is following us we need to vacate the stop before the bus arrives and evicts us. If we end up following a bus we need to find a place to stop and wait for the bus to clear the stops.

I wanted to clear the Spring Bank area this week because next week it will be very busy because Europe's biggest temporary fairground arrives in Hull. It is a great fair, there are the usual small stalls and fast-food stalls and lots of big, fast rides which help you see your fast food again.

The middle ground

2009-10-05T12:01:00.005+01:00

The OSM-talk mailing list has descended into farce.

There are people who want OSM to have a leader, some sort of benign dictator, who will arbitrate over issues like how to tag things properly and people who do not want this at all. There are people who respond to every post regardless of how little they know about the subject and people who get irritated by this. There are people who believe that everything can be solved by writing a wiki page and those who largely ignore the wiki. There are people who believe that new-comers should be vetted or guided before they are allowed to edit the real database and other who create tools to make edits by a new-comer even easier. There are people who think there should be a proscriptive list of tags and others who don't. There are people who think every change to the list of tags needs to be agreed with a vote and others who dismiss voting as meaningless. We have seen our first public resignation from the list, but how many more people have just given up on it and walked away? People are beginning to become entrenched and affiliations are forming on one side or another, yet all these issues crossover to some extent.

So, where do I stand?

The calls for a leader are well meaning but naive. SteveC has been held up as such a leader but is someone with vision the right guy to go through the minutia of shield shapes, shop types, road colours, surface type etc? I don't think so. Is it likely that one person can have the knowledge and the foresight to make binding decisions that will apply across all countries and legal jurisdictions? I very much doubt it. Will one person understand the reason that everyone contributes, so what tags really mean to them? Certainly not.

In spite of a few people shouting it down, open tagging works very well. A consensus has emerged about almost everything. Some people want that consensus carved into stone tablets so no tags outside of the 'rules' can be used. So what will they do to the people who don't follow these rules? Throw them out of OSM? The outcasts will then just take the freely available data and start again (and I'd join them). If you don't throw them out then the only other way forward is to change their tags and start an edit war.

The calls for consistent tagging often mention how much harder it is for software using the data to make good use of inconsistent data, yet these people don't seem to make use of the data - the people who do use it occasionally mention that it really is no problem.

it has been said that some people don't map an object because the tags are not clear. I wonder how much real tagging in the real world these people have done. The real work is gathering data from the ground. It is easy to change a set of tags later rather than go out to an otherwise well covered area to gather the data again for a feature you deliberately ignored.

Some people favour Taglist. This shows the number of times a tag is used allowing a consensus to form, but, like any kind of evolution it has no guiding hand. We get convergent evolution where two different sets of tags mean the same thing. We get broken tags where no thought went into them so they don't stand the test of time.

The biggest problem area is the lousy wiki that is used to document things. Creating wiki pages is easy. Creating a useful wiki page is much harder. Creating a wiki page that is useful and stays useful after various people have tinkered with it is very, very difficult. Creating a wiki page for a new tag is easy. Assimilating the comments to make a tag better is tedious but can be very productive if it is done well by someone willing to accept ideas and not just push their own agenda. The final voting system to then adopt a tag is meaningless. So few people vote compared to the number of active mappers that a majority is worthless and sometimes ignored anyway. Once the tag's wiki page is promoted to Map Features it gets changed later without voting anyway.

Open format tags are very useful for our world. Very few things in life are black and white, so extreme views like 'closed tag lists vs anarchy' really don't help. People contribute to OSM for many, many reasons and all are equally valid. Their reason, their culture, their language, their temperament, their environment, their software and their experience all flavour the tags they use and the things they tag. If we close the list of tags much of this will be restricted.

Do I have any answers?

Create a tagging list to get the issues with tagging off the Talk list. Moderators on busy lists should remind people to exercise restraint, both in not just commenting blithely on every message and also not repeating the same argument over and over. Scrap voting on tags - it gives a false air of importance to the process. Scrap the wiki for tag documentation, replace it with some solid tags in a harder-to-edit form and emphasis Taglist and open format tagging.

These are my ideas. They are not binding. In no way do I intend these to revoke anyone's human rights. You are free to ignore them and/or express ideas of your own, but please, please don't start arguments on OSM-Talk.

Bus maps and a fool

2009-09-24T16:46:00.002+01:00

We've been out checking bus stops again in Hull. We've now checked over half of the stops. Today was a struggle, on busy roads with lots of stops missing. Hedon road was very substantially rebuilt some years ago and I wonder if the old stops were not removed from the council lists and new ones added, although the consecutive numbers would not support this.

Keeping track of the stops was becoming a pain, so I knocked up an overlay for the stops in Hull. I offered the sources for this map to the talk transit list or to extend it for other areas but there's not much interest. I've sent the link to my contact in Hull council so he can see progress.

Something has been bugging me recently. The OSM-Talk mailing list can be very busy and often has interesting or useful threads on it, but lately it has been full of meaningless, circular, argumentative threads, usually pushed along by one person in particular. I'm beginning to dread the meaningless, rubbish that he replies with, to almost anything people add to the list. I wish others would ignore him.

Such a lovely place

2009-09-20T16:32:00.004+01:00

We ventured out on a warm, sunny September afternoon to check bus stops in the Preston Road area of Hull. It is one of the roughest parts of the city, both by reputation and by record. The violent crime record is particularly grim, but on a sunny Sunday all was well. There were plenty of signs about, a few people drinking in the streets, a few youths out with their attack dogs on very short leads, a couple pushing a mini motorbike and an unregistered trail bike along the the street with two toddlers perched on them heading for a local disused railway line and two blokes with a piebald pony on a bit of waste ground, taking turns to ride it bareback using a rope bridle.

We plodded round, photographing everything as we went. It sometimes draws attention but not really much today, except for one point where a young chap followed the line of the upward-pointing camera and stared into the sky beyond the bus stop sign, looking for what we were photographing. I didn't like to point out that it was just a bus stop and we left him looking for UFOs.

We have now checked about 45% of the stops in the city. I'm going to send another batch of updates to the council for their comments.

On the way home we saw a buzzard very close to home. Although they're making a strong comeback in lowland Britain, so they are not especially rare there any more, it's still a pleasure to see one circling overhead.

A question

2009-09-16T17:06:00.002+01:00

We dashed out on a busy day to grab a few bus stop checks. We managed a couple of dozen. The email lists have discussed how to tag some of these and one thing that came up is that some stops have a raised curb to assist people on wheels to get on the bus. I don't know the official name of this feature so I've tagged them as ramp=yes. I sent an email to the bloke in the council who's interested in these checks to see what they call them. It turns out that he knows a friend of mine too - it's a small world.

I need to review the photos for some of the stops I've already checked to see if they have ramps too. The tagging of stops might yet change by adding features, like a shelter or a ramp, to a bus_stop tag which is a contemporary way of tagging. I'm not sure about comma or semicolon separated lists though.

What button?

2009-09-14T16:28:00.002+01:00

The NaPTAN load of bus stops has given us reasons to revisit Hull. The city was chock-a-block over the weekend as the Round the World Clipper race started from the marina. Today the city was back to normal and we went into the city centre to walk round some of the stops. The GPS reception was about the worse I've ever seen. Most of the time it had no position lock at all, and when it did, briefly here and there, it was so poor that I ignored it. I took lots of photos to position the bus stops on the streets.

The stops were very poor, many did not have the NaPTAN code on them, the postions were poor and there were extra ones and missing ones. So far the NaPTAN data has been pretty good, but in the city centre it's not been good at all. The absence of GPS locations didn't help when it came to editing, but I think it's pretty good.

One thing I did find was a placebo button on a crossing. The junction is controlled by traffic signals, the crossing is over a one-way street, so the traffic signals for the crossing are part of the junction signals. There used to be a button on the crossing, but now the button has been covered over. There looks like there is a button, but it doesn't do anything. It just makes you feel as though you have requested the lights to change to make you feel better, hence it is a placebo button.

Lets move on

2009-09-10T18:32:00.004+01:00

We mapped the last chunk of streets in Goole today. There's still stuff to complete for the town in details like some POIs and maybe some footways, but I'm going to leave it to someone else. I'm moving on to map somewhere else.

I have used a Yahoo email account for the OSM mailing lists. I wanted to keep all that separate from my normal mail. Thunderbird makes managing separate email addresses very straightforward, so all was well. Recently though, many messages were being delayed. The mail threads didn't make sense, I was getting replies to emails that I hadn't seen yet. When I added a message it was hours before I got it back again. So I set up a mail account on my testing domain which now seems to work very quickly. I just forget to change my name, so the lists got a message from 'osm' - not very helpful.

I did ask Yahoo about this, they sent me an email, which arrived immediately, so there was no problem apparently.

More of Goole

2009-09-07T17:40:00.002+01:00

We went to Goole today, to map a bit more of the northern part. I can say that motivation to map Goole is low - I just can't generate any interest in the place. I've mapped all sorts of places now, pretty villages, busy towns, grotty estates, open country and loads of housing estates, but Goole somehow in just not exciting.

There's more to do to finish the place so another visit or two is required. One should include a walk through the docks on a public footpath which might be interesting. I hope so.

Council update

2009-09-06T17:18:00.002+01:00

We've been out checking bus stops again. We now have checked about a quarter of the stops in Hull. We have done some of the busiest roads so some gentle routes around quieter parts today made it easy. One of the stops is labelled as St Bede's church, so that helped add the name of a rather strange church that has no name board up but does not seem abandoned.

I have a sent a spreadsheet off to a chap in Hull City Council's transport team. It lists the stops we've checked and add the comments and issues, like stops with no signs, or no code on the sign or no stop at all. I'm interested what he thinks of our efforts - he has already said he wants to see it. I have not detailed the stops we have moved, mostly less than 20 metres, unless they were completely wrong such a the wrong side of a junction, or the wrong side of a street or on the wrong street. Most of the stops have been good, well labelled, and well positioned. There's just a lot still to do.

Pub reopens

2009-09-04T17:17:00.002+01:00

One thing I like about OSM is the immediacy of it. I heard today that The Minerva is reopening, which is against the trend for pubs up and down the country. The Minerva was a great pub, it had a micro brewery attached where they brewed Pilots' Pride and they also kept a wonderful pint of Tetleys too. They served good food and being on the waterfront it's a good location. I hope the revamped pub is as good as the old one. A few minutes after I heard this news the pub was re-instated to the map and a bit later the renderer had redrawn it.