I know how to use the "forward" and "backward" roles, but is there a rule for ordering the ways? For example, when there are one-way streets. When I download a relation as a GPX track with sections which are different in both directions, the track has several segments and is not compatible with my Garmin GPS. A solution would be to make 2 relations, one for each direction. This does not seem to be practiced on OpenStreetMap. asked 24 Sep '12, 15:51  bergamote |
2 Answers:
Cycling and walking route relations are not generally kept ordered in OSM. Users who require an ordered version can post-process the data. answered 25 Sep '12, 09:30  Richard ♦ |
What type of relation are you looking at? Public transport relations (and other strict linear features) are indeed ordered such that they form a continuous route. Types of relations that don't require strict ordering aren't necessarily ordered, by their very nature. answered 25 Sep '12, 08:12  Roland Olbricht 2 I'm particularly interested in biking and hiking relations. The problem is when a marked route does not use the same street in one direction for a short section. For example here. This is the GPX track. (25 Sep '12, 08:28) bergamote |
When editing relations using JOSM, I try and sort the members, as it makes finding and filling gaps easier. It is very easy to miss a short section, such as steps or a footbridge, in an unsorted relation.
Thank you Richard. This is not a problem to order a relation when the signposted route uses the same road in the opposite direction. If you look at this relation as a GPX track, there are straight lines connecting the five sections where the route is different on the way back!
In fact, I see three solutions:
- make 2 connections, one for each direction;
- continue the relation for the way back by copying the relation's members and connecting the 5 sections that are different;
- as you say, post-process with software, which is not within the reach of everyone.
osm.org generally doesn't aim to provide data in a consumer-friendly format - it's principally a site for the use of mappers. Rather, we rely on third-party websites to do that.
I would hope that, if there were enough demand, a third-party site would be established to supply route relations properly ordered in .gpx format. Certainly it would be wrong to impose an extra burden on mappers (or our hard-pressed tool authors) just to suit the needs of one particular group of users.
OK, now I understand. I asked for something that is not easy to implement. Anyway, a site like http://www.waymarkedtrails.org/ is excellent, but the downloadable tracks are not always usable on a GPS.