OpenStreetMap
waychains, wherecamp, potlatch, OS, and the last 2010 winter pub meet-up ever!
Posted by Harry Wood on 25 March 2010 in English. Last updated on 27 March 2010.My waychains tool has been analysing U.S. interstates for just over a month now. During that time the stats have inched up and down a bit, but mostly held at about 26% paired (currently 290 paired out of 1112 different ref values)
The map showing pairing progress still looks about the same as it did in January:
So not a great deal of progress so far.
UPDATE: Turns out the above graph is bollocks. See update diary entry
You can read about how it works and what kind of TIGER Fixup it is prompting you to do on the: 'Waychains TIGER Fixup' page. And here's a link to the waychains tool itself
At Where Camp EU I did a talk to spectacularly launch this exciting new tool, but it was too early in the morning for spectacular launches, and it was up against lots of other interesting things in the first session slot.
It's easy to lose interest in the big fat hairy problem of OpenStreetMap U.S. now that I'm no longer at CloudMade. But it is pretty key to OpenStreetMap's plans for world domination as well. We should be able to persuade some of those guys to join in. I've heard they have a quite a big technical community over there :-)
Where Camp EU was the a London geo-unconference which I was helping to run. I was pleased that OpenStreetMap managed to have a pretty heavy presence there, with lots of interesting OSM related sessions (see session list) Hopefully we put across a good message to any audiences who knew less about it. For OSMers a particularly interesting session was Richard Fairhurst's talk about Potlatch 2. This is a development focus at the moment. Looks like there's some lovely new features in store. For example, Richard described a means of importing datasets while checking/merging data by hand, which will be built in. Nice!
So the exciting news this week is this bit of Gordon Brown's speech on Monday: "following the strong support in our recent consultation, I can confirm that from 1st April, we will be making a substantial package of information held by ordnance survey freely available to the public, without restrictions on re-use. Further details on the package and government’s response to the consultation will be published by the end of March." I responded to the consultation, as did many people, via the nice site set up for the purpose: http://osconsult.ernestmarples.com/ I like to think that this deluge of emails must be the "strong support" he's talking about. It remains to be seen what the "substantial package" is, but we shall find out soon enough!
And now for the most important news of all....
We've got a pub meet-up tomorrow (Thursday) night. Hereford Arms near Gloucester Road 7p.m.. This will be the LAST winter 2010 pub meet-up ever! Don't miss it! (p.s. I actually missed the previous one myself, but I will be there tomorrow)
Discussion
Comment from RussNelson on 25 March 2010 at 12:40
i'm confused. I already fixed up all of NY's Interstates. Now I have to go thru them all againn, I guess, and add ref tags, sigh.
Comment from Harry Wood on 25 March 2010 at 13:04
Well the intention was to discover other more important problems (oneways pointing the wrong way, bits of interstate without a way in each direction, etc) But unfortunately it does seem to have mostly uncovered botched up 'ref' tags, which is a less interesting kind of problem. I don't think we need to add ref tags in many places. It's mostly fixing weird problems with the exiting ref (and int_ref) tags. Some of it requires a bit of local knowledge of how these roads are named.
Comment from Baloo Uriza on 25 March 2010 at 21:29
I wouldn't make this validation dependent on the ways being tagged with refs, but rather members of route relations as that seems to be the way to handle routes going forward rather than trying to mangle way attributes to describe a route.
Comment from RussNelson on 26 March 2010 at 01:31
I'm doubly confused. The entirety of I-81 and I-88 in New York State has ref="I 81" or "I 88" (strictly speaking, there are a few semicolon-separated pairs in there, but you know what I mean). Shouldn't they show up in your map as completed?
Comment from Jean-Marc Liotier on 26 March 2010 at 09:31
Would waychain checking work for motorways in other countries ?
Comment from Harry Wood on 26 March 2010 at 15:53
Aha. Steve's blogged me. That's why this has got some attention. I thought it was just the green and ref graph getting everyone excited.
@Paul Johnson - I've added a reply explaining my thinking about relations.
@RussNelson - I've added some more details about refs with ';'s in them to the the wiki page. So I 88; NY 7 for example, reveals a curious gap caused by short length which is tagged only "I 88" not "I 88; NY 7". To find problems, you tend to look at where the ends of the blue lines are pointing, and ask yourself why the waychain is ending there. Local knowledge can be useful. For example is "NY 7" just another name for the whole length of "I 88"? in which case there should be no ways tagged with just "I 88".
@Jean-Marc Liotier - Yes although it might not be very interesting. In any country where motorways have been mapped by the OpenStreetMap community (gradually, "manually", one by one) The data is of a much better quality than the U.S. TIGER data
Comment from Harry Wood on 26 March 2010 at 15:56
Aha. Steve's blogged me. That's why this has got some attention. I thought it was just the green and red graph getting everyone excited. Incidentally I've just discovered something which might mean the graph is entirely wrong! checking now.
@Paul Johnson - I've added a reply explaining my thinking about relations on the talk page there.
@RussNelson - I've added some more details about refs with ';'s in them to the the wiki page. So I 88; NY 7 for example, reveals a curious gap caused by a short length which is tagged only "I 88" not "I 88; NY 7". To find problems, you tend to look at where the ends of the blue lines are pointing, and ask yourself why the waychain is ending there. Local knowledge can be useful. For example is "NY 7" just another name for the whole length of "I 88"? in which case there should be no ways tagged with just "I 88".
@Jean-Marc Liotier - Yes although it might not be very interesting. In any country where motorways have been mapped by the OpenStreetMap community (gradually, "manually", one by one) The data is of a much better quality than the U.S. TIGER data, and this crude tool would just give false negatives.
Comment from Baloo Uriza on 26 March 2010 at 17:47
I think you might just need to get over your fear of relations, given that relations really are the simplest way to describe routes, and frees ref tags on ways to handle stuff like actual way-bound references (like DOT numbers).
Comment from Harry Wood on 27 March 2010 at 16:42
Oops. Turns out we are making some progress with ref fixup. See my update diary entry