A lot of areas in London still look very poorly mapped. A few examples:
That’s between Buckingham Palace and Piccadilly Circus, just at one of the Olympic venues:
I can give tones of such examples, but you get the point anyway. If you look at how buildings are mapped in London in general, you’ll see that even zone 1 is far from being well covered:
And this is in spite of the fact that Bing imagery is just fascinating almost everywhere in London!
What I would like to suggest is to run a global online mapping party and trace as much buildings as we all can before Summer, thus giving future Olympics visitors a more complete map than we have at the moment.
I know that many contributors are against such massive “armchair mappings”. I respect this view and the reasoning, but let me go through the arguments I remember and discuss them:
- Having all building outlines does not mean that the map is complete; we are still missing addresses, POIs and heights.
- Because imagery is usually old, there is a chance to miss a building or map a demolished one.
- Such online mappings harm local communities.
Ok, the first one: Indeed, it’s sometimes hard to distinguish between a remotely traced area and a properly surveyed one when you’re looking at a slippy map thinking of the location for the next mapping party. But we’ve got other tools, don’t we? Just with three basic steps in JOSM I can determine what areas are not surveyed: 1) search for “building=* AND -“
addr:housenumber" -"addr:housename"” 2) delete the selection 3) look for empty areas. Pretty simple, isn’t it? Now guess, how many buildings with names/numbers are there in Central London now? Less than 20%. No one seems to feel any worries about that so far.
Now about the reliability of the imagery we have. Bing hi-res (20) is relatively old (Aug 2007) but zoom level 19 and less are Oct 2011! And London is not Dubai, where the landscape changes every year :) In my personal experience I remember only two cases of outdated Bing in London: a demolished building near Manchester Square and Angel centre that has been removed and rebuild on the same place, slightly changing its shape – all now seen on new imagery. The rest of the buildings I’ve surveyed are exactly the same as on Bing. They’ve been there for more than a hundred years and will stay the same for another hundred or more. So isn’t it worth adding much more data with just a few mistakes than having almost no newly added data at all?
3. If we have pre-traced buildings, we’ll be able make our mapping parties more interesting and productive. We’ll be able to cover bigger areas, as it used to be years ago when mostly street names and some POIs were collected. I don’t really mind spending an extra hour on walking papers and photos of opening hours signs, but the thing that I’ll have to spend extra 2 hours on tracing the architecture in that additional “cake slice” stops me every time – that’s too much. I usually pre-trace the outlines the day before anyway just with Bing, and they change very rarely after the party, being honest. Supplementing and polishing in this case is easier than doing everything from scratch — it’s not the same as hacking someone else’s code :) London is really huge and even if we have all buildings mapped, there will be still hell a lot of work for everyone to do on mapping parties and between them. Apart from that, Russian experience in doing these online mapping parties shows that such things bring new people to the community afterwards.
Here is another argument in support of the idea: Not all uses of OSM involve addresses, POIs etc. There are many services that just want our data for the background, for instance, foursquare or TFL’s online countdown service (zoom in to see buildings) — that’s millions of users daily, and they want a fancy map now, not in 5 years. Why to make those users think that a cited “OSM and contributors (whatever that means)” has an very incomplete map “with even no outline of my office”?
Thus, I have a strong feeling that such experiment won’t harm the map or community and instead add a huge value both to data users and contributors in London. I do believe that OpenStreetMap can and must be very popular among the Olympics visitors, especially those that will use offline apps on their smartphones. And 6-8 local mapping parties we’ll have before July is far not enough, we do need help from overseas.
This online mapping party can last for weeks starting soon, before it gets warm enough to go out and map, and we’ll invite everyone to take part. Maybe it can even be a project of the week, month or whatever. We can also organize some local offline workshops for newbies or something like this to support the London 2012 mapping challenge and bring new people in.
I’m not going to take any further actions like creating mapcraft cakes and wiki pages with instructions as I am not Londoner and don’t feel like can launch such stuff without everyone else’s approval. This note is just a call for an open discussion of the problem. If other OSM contributors in London agree with this idea, we’ll think of what we should do on one of our pub meet-ups and see how to organize the process.
Please leave your thoughts in the comments.