Tag Archives: road safety

Mapping for pedestrians

One of the odd things about contributing to OpenStreetMap is that you have no idea who is using the maps and the data. You spend hours, weeks, months, years even building up a wonderfully comprehensive database of geographic features in the area, all because it’s fun, because you believe in the project’s ideals or you need the data for your own project. But does anyone else use it? It would be depressing if the answer was “no”.

So I get cheered every time I see documents like this:

That’s an excerpt from a presentation by Southwark Living Streets. They took the Mayor of London’s transport advisor around Elephant & Castle to show how unfriendly and dangerous the area is for pedestrians, and illustrated the whole thing with OpenStreetMap. The chap who made this loves OSM, he told me he realised how useful it could be when he noticed we had put in all the footpaths through estates, making OSM the only map that reflects the reality for pedestrians in the area.

It was our coverage of footpaths that led to OpenStreetMap being used by parents challenging a school’s decision that they were outside the catchment area.

I also regularly see OSM used by cycling campaigners, for example this presentation on a cycling campaign that’s also about the Elephant & Castle area.

Then there was my collaboration with residents local to the Heygate Estate who wanted to map the trees that under threat from the redevelopment of the estate. That, I’m happy to say, has resulted in many of the mature trees being protected in the new plans.

So we have useful maps, and powerful tools for community campaigns if there’s an OSM expert about to help out.

But as I wrote last year, there’s a whole other world of data we could be adding, especially for groups concerned with streets that are designed for pedestrians and cyclists.

ITO have been beavering away on lots of amazing maps that show off this kind of data. These are two maps showing the “walkable city” on the left (the blue lines show footpaths and pavements broken up by black roads) and speed limits on the right (green is for 20 mph, orange for 30 mph).

Here are a few in an area I’ve done some work on, just to show what’s possible:

With a few tweaks to the Potlatch 2 editor on the OpenStreetMap homepage, anyone could easily add all this metadata to streets. There are presets for speed limits and surfaces, but not – yet – for sidewalks. If we could get them in – here’s the enhancement request – I think all those community campaigners already using screenshots of OpenStreetMap might just get interested in contributing data.

How great would it be if Southwark Living Streets could print out a special “walkable city” map of Elephant & Castle for their next presentation to the Mayor of London’s transport advisor?

Tagged , , , , , , , ,

Getting speed limits into OpenStreetMap

I’ve started trying to add speed limits data to roads in my patch of Southwark. Two things made me start looking at them…

First, I go everywhere by bicycle, which means speed limits and London congestion are of very little relevance to my journey times. But I noticed that journey planners like CloudMade’s offer wildly optimistic journey times for cars. Even ignoring congestion, I thought, they can’t be taking account of speed limits, which across London are lower than the national assumptions. For example, most main roads have a 30 mph speed limit and a growing number of roads, residential and main, have a safer 20 mph limit.

The second reason is that speed limits have been a big issue for cyclists recently, featuring in campaigns around issues like Blackfriars Bridge and Southwark’s Transport Strategy.

So here’s a snapshot of our data around Peckham and East Dulwich after a few sessions on my evening commute, using ITO’s excellent tool:

Orange roads are 30 mph, green are 20 mph or lower, grey are main roads without any data; all the minor roads without speed limit data just show through from the background. Getting more roads down to 20 mph will make them much calmer, more pleasant and safer for people on foot and bike.

Not a bad start, but we have a long way to go! I could probably get data out of TfL and Southwark Council. But I’m interested in seeing what I can actually find on the ground, both because the two sometimes don’t match up and because it made me aware of just how varied the signposting is.

With some roads it’s very obvious – it’s a short residential road with a signpost and a huge “20 mph” painted onto the road. On other roads you could easily miss it. Walworth Road has a 20 mph limit, but if you missed the single signpost going either north or south past endless distracting shops, signposts and shoppers, and buses that often block your view, you could be forgiven for assuming it’s 30 mph like most other roads.

Back to OpenStreetMap, it would be good to get better coverage of speed limits. I notice that some parts of the country like Norwich are very well mapped, while London – with the exception of my experiment, Islington and a little bit of Tower Hamlets – barely has any.

One for a winter mapping party, Harry? Or maybe another good reason to get cycling and pedestrian groups interested? I’ll talk to the Southwark campaigners…

Tagged , , , , , ,
Follow

Get every new post delivered to your Inbox.

Join 89 other followers