On Jul 10, 2014, at 2:20 PM, Jesse Crawford wrote: > An example situation is visible here: > http://www.openstreetmap.org/#map=18/34.05688/-106.89005 > > Both California St and the nearby I-25 are two-way streets made up of two > parallel one-way streets. This has the advantage of thorough data, but it > introduces two issues that I see: > > 1) Information on crossover points is usually insufficient for surface > streets of this type, at least in the US. It is possible to make U-turns and > left turns from California St in many more places than the map shows, but > considering that these places are just small cuts in the divider it seems > excessive to make a small road object for each one. > > 2) When you zoom out, the two sides are still rendered separately but the > lines begin to overlap. It begins to look strange, e.g. two "California St" > labels on slightly different baselines will appear right next to eachother, > with one representing each side. A reference tying the two ways together > might provide map renderers information that they could use to prevent this > situation. >
Looking at your example my first impression is that the big problems in this area are off the topic of this thread: 1. The area is still a "Tiger Desert" where nearly every road still has a tiger:reviewed=no tag. 2. It is not obvious, due to lack of GPX tracks, how well the satellite imagery is aligned so accurate "arm chair" mapping is problematical. 3. Tags that would really assist some data consumers that focus on routing and driving directions are missing (e.g maxspeed=*, locations of stop signs, etc.). 4. And, like much of the U.S., addr:street=* and addr:housenumber=* information is missing too. You can't route to it if you can't find it. :( But getting back to your two points: 1. Most of the crossings I see in the Bing imagery in your example area are at cross roads and entrances to parking areas. They exist that way in "real life" and can be mapped that way in OSM, so it does not seem excessive to me to add the occasional small connectors needed in areas where there is no cross street, etc. 2. There is already the concept of route relations where segments of a through way, even with dual one-way carriageways, can be shown to be related. I haven't seen it done for things like your California Street in Socorro example, but look at how this county route in California has both the north and south bound carriage ways all shown to be related: https://www.openstreetmap.org/relation/1205049 I don't know of a renderer that uses this to decide that only one set of label text and/or highway shields is needed, but the data is there for them to use if they want.
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