Hello, I'm looking for a way to tag designated areas where cyclists wait to safely make a far turn (in right-hand-drive regions, a left turn). I'll call them "left turn boxes" for short though pointers to a better name would be welcome!
They're paint-designated places for cyclists to wait to do a two-stage left turn from the right edge of the roadway. In regions that allow right turn on red traffic signal, they are usually coupled with no-right-turn-on-red restrictions. See for example https://bin.piorkowski.ca/2019/two_stage_left_turn.png - screenshot of Esri imagery for https://osm.org/node/25813496 at 43.6670781,-79.3746698 To my understanding, this is not the same as a cycleway=asl (advanced stop line, "bike box") in OSM as an ASL is _behind_ the stop line and behind the pedestrian crossing, and thus not really easily usable for left turns - cyclists would have to cross the stream of pedestrians to get into the box. I am aware that in many regions left turn boxes are common to the point of being basically the default at bigger intersections, and thus doesn't really need tagging. However, the area I'm mapping has probably a single digit amount of them. As they make left turns a lot safer, I would like to map them so that routers can prefer them. Does anyone know of an established way to tag these that I could adopt? To tag unambiguously and in a computer-readable way, I guess it'll need a relation from-to-via? Previously discussed in OSM Canada Slack, #general channel on October 16, 2019 https://osm-ca.slack.com/archives/C36U69X18/p1571266663002600?thread_ts=1571265183.002300&cid=C36U69X18 but we didn't come up with much. Looking for an alternatives to a relation, I came up with https://bin.piorkowski.ca/2019/possible_asl_node_tagging.png and described it as following: "I suppose something like this could work to avoid a relation, routers would then have to look for cycleway:asl=two_stage_left_turn a little to the right of where they'd like to make a left turn. Advantages: no relations - they seem to be somewhat disliked in OSM; representation as turn-right-then-U-turn is somewhat like how cyclists are used to turning left at hostile intersections. Disadvantages: the portrayed distance to turn off to right is further than the actual distance; routers might well find it easier to find left turns as they would normally and then prioritize those with a bicycle_two_stage_left_turn relation" But frankly I don't really like that solution much, and the other editor contributing in the Slack thread thought it would be "misleading, since the box is on a way not actually involved in the turn". Thanks for any leads! --Jarek _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
