> I would not expect to see something like that, in any of its regional variations (green walking person/red stationary person in much of Europe) without related lights controlling traffic.
So, in the case of a pedestrian warning beacon, which does not control traffic in the cases you've mentioned, how would you tag the crossing? crossing=uncontrolled? Even thought it has pedestrian-facing lights *and* lights intended to warn traffic about pedestrians? There's another user in this thread who thinks the polar opposite and that the lights directed at traffic are irrelevant. Who is correct? What does the tag mean? This is making me think that my other proposal should be revised so as to separate out pedestrian signals from street traffic signals entirely. Something like crossing:pedestrian_signals=yes/no/(type) and crossing:traffic_signals=yes/no/(type) > Not necessarily. Most countries there probably is something, if only tactile paving for the blind. I think I miscommunicated - I'm referring to that intersection in the picture only, where the crossings are marked with the ladder pattern. >> If we tag that as crossing=traffic_signals, have we correctly and consistently communicated all of that information? > Maybe. People are capable of misinterpreting anything. Of course, but that's the same regardless of whether a tagging schema is awful or ideal. Earlier, the necessary conditions for crossing=traffic_signals were solely (1) signals that control pedestrians and (2) signals that control street traffic. But now, at this intersection, crossing=traffic_signals implies markings? This is a contradiction. It is simply not possible for both to be true. So you can see my dilemma in trying to use such a tag. Keep in mind, all I want to describe is whether a crossing has markings and whether it has pedestrian signals. That seems like something just about any person on the street should be able to answer, but the schema makes it difficult to tag. > I would say that both pedestrians and traffic have to be controlled. Controlled pedestrians and uncontrolled traffic is insane. Controlled traffic and uncontrolled pedestrians is traffic lights. Not according to most definitions of "controlled", in terms of traffic lights. A stop sign is a form of traffic control. Also, someone in the other thread claimed that dropped curbs were a control. Someone in this thread says a marked crossing is a control. Nobody agrees on what a control is in OpenStreetMap, so how can we ever trust data for "uncontrolled"? I'd guess that almost nobody is using it for anything other than a delay on a router (car might have to stop) or some generic visualizations of feature density. They can't, not reliably. > The pedestrian-facing lights and vehicle-facing lights don't even have to be on the same pole, but they should be positioned such as to control the pedestrians and traffic at a crossing and be operated in synchrony by the same controller. Together they constitute a single crossing. I wholeheartedly disagree. A crossing is not the signals. A crossing is where pedestrians cross the street. A crossing can *have* signalization: signals are a property of a crossing. This is similar to how a crossing is not an island and why crossing=island was a bad idea. > Oh, and you can have two independent crossings within a few yards of each other which handle one direction of traffic flow on a road with several lanes (...) As footways, I would map this as three elements: all are footway=crossing, the central island is crossing:island=yes, the other two are... well, I don't know, really. That's what I'm asking questions about. Maybe crossing=traffic_signals. On Fri, May 10, 2019 at 4:31 PM Paul Allen <pla16...@gmail.com> wrote: > On Fri, 10 May 2019 at 23:59, Nick Bolten <nbol...@gmail.com> wrote: > >> >> - A crossing might be marked on the ground >> >> > Are there traffic signals which control BOTH traffic and pedestrians? >> If so, >> > crossing=traffic_signals. If there are JUST road markings, no >> crossing=traffic_signals. >> >> I interpret this to mean: the necessary condition for using >> crossing=traffic_signals is that there are signals controlling both traffic >> and pedestrians. If only one or the other, it is not a >> crossing=traffic_signals. >> > > That's how I intended it. If it only controls traffic then it's ordinary > traffic lights (regardless of > whether people use it as a place to cross). If it only controls > pedestrians it's insane: "Yep, > you can cross now, don't worry about those cars because there's nothing I > can do to stop > them." > > > >> - A crossing might have lighted signals for pedestrians to cross >> >> > Define what you mean by lighted signals. If you mean a Belisha Beacon >> or something else that WARNS motorists that pedestrians cross here but does >> NOT control traffic and pedestrians then it's not >> crossing=traffic_signals. A warning light is not a traffic signal. >> >> In this case, I was thinking of a specific "walk/do not walk" lighted >> signal. >> > > I would not expect to see something like that, in any of its regional > variations (green walking > person/red stationary person in much of Europe) without related lights > controlling traffic. > >> >> > That's crossing=traffic_signals IF it also controls pedestrians. >> Walk/Don't Walk ot Red/Green figures or whatever. Otherwise it's just >> traffic lights. Even if people can cross there, it's still just traffic >> lights because the crossing (by people) Isn't controlled, just the traffic >> is. Traffic has to stop when the lights tell them, the pedestrians take >> their chances and are uncontrolled. >> >> I take this to mean that the signals do not need to be colocated in order >> to tag crossing=traffic_signals, such as in this scenario: >> https://www.colchestervt.gov/ImageRepository/Document?documentID=185. >> >> - There are markings on the ground >> > > Not necessarily. Most countries there probably is something, if only > tactile paving for the blind. > > - There are pedestrian-facing signals >> - There are traffic signals at the intersection controlling traffic >> > > Those are the two important bits. Along with the fact that they are > operated by a single > controller. No point to them if they operate independently. The whole > idea is that they stop > traffic to let pedestrians cross and stop pedestrians to let traffic flow. > > There may be a button that pedestrians can press to signal their > presence. In some countries, > in some cases, that button is a dummy. A light comes on to tell you that > you've pressed it but it > has no influence upon the timing cycle. The timing cycle may be > controlled by road sensors, > or by time of day, or may have a fixed duration. Presence or absence of a > button is irrelevant. > > >> If we tag that as crossing=traffic_signals, have we correctly and >> consistently communicated all of that information? >> > > Maybe. People are capable of misinterpreting anything. > >> >> As an aside regarding the term "controlled", the OSM wiki doesn't >> actually say any of this about whether it's traffic or pedestrians or both >> being controlled. What it actually states is that crossing=uncontrolled is >> equivalent to a marked crossing or "crosswalk". A marked crossing can have >> or lack all forms of traffic signals that we've discussed. >> > > I would say that both pedestrians and traffic have to be controlled. > Controlled pedestrians and > uncontrolled traffic is insane. Controlled traffic and uncontrolled > pedestrians is traffic lights. > > > *Sigh* Was all this about pedantry? The same interlocked mechanism >> controls two sets of lights on the same pole, one set controls vehicular >> traffic the other set controls pedestrians. I didn't mean that both >> pedestrians and motorists stare at exactly the same set of lights. >> >> That's not pedantry, it's the precision that we need to describe >> crossings. Are we mapping based on lights or a connected signal apparatus? >> That's an actually important question. We should be able to say that >> clearly to new mappers and embed it into mapping tools. >> > > The pedestrian-facing lights and vehicle-facing lights don't even have to > be on the same pole, > but they should be positioned such as to control the pedestrians and > traffic at a crossing and > be operated in synchrony by the same controller. Together they constitute > a single crossing. > > Yes, you're going to have to spell out all the variants. Like the image > you linked to where lights are > suspended from cables in the middle of the road and only face traffic, but > they're part of the same > single crossing. Traffic-facing and pedestrian-facing lights for the same > crossing might be on > different poles. > > Oh, and you can have two independent crossings within a few yards of each > other which handle > one direction of traffic flow on a road with several lanes. Each crossing > goes from one > sidewalk to a central refuge, you walk along the refuge a few yards then > cross the other direction > of traffic. They usually operate independently to increase traffic flow > by not stopping lanes in > one direction just because people are crossing the lanes in the other > direction. One crossing > or two? I'd say either is acceptable depending upon the level of detail > the mapper is putting in: > ideally two crossings, but to get the job done quickly it's one crossing. > Same thing for > crossings at a crossroads, except it would be one or four crossings. > > Incidentally, in the UK, on staggered crossings like that audible crossing > alerts are legally prohibited. > You could hear the sound of one crossing and interpret it as the alert for > the other crossing. > So audible alerts are prohibited but the box housing the signal button is > then legally required to > have a "rotating cone" (it's optional in situations where audible alerts > are legally allowed). > See > http://www.gosocial.co/pedestrian-crossings-have-a-secret-button-this-is-what-its-for/ > > -- > Paul > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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