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Good morning. I'm adding some nodes in my town, trying to indicate crosswalks and traffic signals. One example here Some of them are only traffic signals (highway=traffic_signals), but others are pedestrian crossings (highway=crossing) with traffic signals near them. I think that I'm not doing it well. Because my low English level, sometimes I don't understand correctly Wiki. As far as I understand, pedestrian crossing with traffic lights have to be tagged as highway=crossing + crossing=traffic_signals. (Nowadays I've not added the tag "crossing=traffic_signals", so I have to correct them). But, is it necessary (or convenient) to add a node near the pedestrian crossing where the traffic signal is? I'll appreciate all your comments. I don't want to continue this labour if I have doubts. Thank you in advance. |
The question has been closed for the following reason "The question is answered, right answer was accepted" by odce72 16 Dec '13, 20:37
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As other people said before, many times there is no single "right" way to tag things in OSM. I usually tag pedestrian crossings and vehicle crossings following simple rules: highway=traffic_signals are used whenever vehicles must obey to the traffic lights. For example, when two roads intersect, the highway=traffic_signals would be applied to the node at the intersection.
(In the image above, the crossings do not have traffic lights in them) highway=crossing + crossing=traffic_signals are used when pedestrians must obey the traffic lights. (See image below) If both pedestrians and vehicles must obey the traffic lights, there would be two nodes, one with highway=traffic_signals where the vehicles must stop and another with highway=crossing+crossing=traffic_signals where the zebra/etc is. If there is a crossing, but without traffic lights, it would be tagged as highway=crossing (and optionally crossing=* to specify the type of crossing) This way, it is possible to clearly separate the pedestrian and the vehicles "rules". Vehicles need to obey the lights at highway=traffic_signals and pedestrians must obey the lights at crossing=traffic_signals. I always put the node tagged highway=traffic_signals or highway=crossing on the way (never besides). Also, sometimes it may be needed to add a way with highway=footway (or other like it) between two or more crossing nodes, making shortest path routing possible between crossings placed on long disjointed ways.
This makes a nice rendered map but... many contributors put the "highway=traffic_signals" on every traffic light position, with or without pedestrian crossing. And apart rendering, it would be important to know which traffic signals are synchronized. This could be helpful for routers adding time penalties on traffic lights. Counting them becomes a real challenge since nobody is following the same rules.
(17 Dec '13, 09:46)
Pieren
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First, as always at OSM, there is no single "right" way to tag something, but various approaches that have different pros/cons. Here the crossing lanes have a dedicated traffic light that is tagged highway=crossing, crossing=traffic_light for the pedestrian footways. Keeping the traffic light and the crossing together at a single node keeps the semantic interpretation (making a computer understand that there is a place where people can save cross a highway) easier.
(12 Dec '13, 21:32)
aseerel4c26 ♦
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Hi read these as well, https://help.openstreetmap.org/questions/1489/how-to-tag-traffic-lights-on-pedestrian-crossing, just by typing 'how to tag traffic lights' Some of us choose your tagging scheme (my choice, moore accurate) but a single node at the crossing can be found as well. |
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Thanks for your answers. So, I think I was doing it well, or not too bad :P I´ll follow MCPicoli's explanation, If both pedestrians and vehicles must obey the traffic lights, there would be two nodes, one with highway=traffic_signals where the vehicles must stop and another with highway=crossing+crossing=traffic_signals where the zebra/etc is, because it's the best approach to the reality where I live, and it's the way I began to tag. Obviously, where there is only a traffic light (without a crosswalk) , I´ll tag one node with highway=traffic_signals. And, where there is only a crosswalk (without traffic lights that pedestrian must obey), I'll tag one node with highway=crossing. Again, thanks for all your answers. |
meta @odce72: you do not need to "close" after accepting (and it is not done usually). See e.g. unanswered q.s ("open questions without an accepted answer").
@aseerel4c26 Thanks for your comment. I didn't know it.