Add quest for flashing_lights

[knkski]

General

Affected tag(s) to be modified/added: flashing_lights
Question asked: Does this crossing have flashing lights to warn about pedestrians?

Checklist

Checklist for quest suggestions (see guidelines):

• 🚧 To be added tag is established and has a useful purpose
• 🤔 Any answer the user can give must have an equivalent tagging (Quest should not reappear to other users when solved by one)
• 🐿️ Easily answerable by any pedestrian from the outside but a survey is necessary
• 💤 Not an overwhelming percentage of quests have the same answer (No spam)
• 🕓 Applies to a reasonable number of map data (Worth the effort)

Ideas for implementation

Element selection:

Pedestrian marked crossings without traffic signals on busy roads (i.e. not highway=residential etc.)

For starters only in the US or even limited further to certain states within the US.

Metadata needed:

Not sure. These crossings are common around me in the US

Proposed UI:

This is what the crossings look like near me:

https://upload.wikimedia.org/wikipedia/commons/0/0a/Bike_and_pedestrian_crossing_in_Portland%2C_Oregon.jpg

UI that asks "Does this crossing have flashing lights for pedestrians?" and presents "yes", "no", or "button" would capture ~90% of the tag values. Adding "always" and "sensor" would get up to ~99% of values, and allowing for multiselect would capture 25 uses of "button;sensor", but is probably too complex.

The UI would have to have some thought put into the "Traffic Lights" question, and maybe merged with it. The UI might present the options above when asking that, for a question like "Does this crossing have traffic lights?" with answers of "No lights at all", "Yes, pedestrians must wait for the lights", "Yes, pedestrians push a button to trigger flashing lights", "Yes, flashing pedestrian lights are always on", etc.

I looked to see if any issues existed for this and didn't find any other than #5471 mentioning it in the comments.

[mcliquid]

In my German-speaking area, such flashing lights are extremely rare (only 1 out of 2892 crossings in my district).
So let me ask you a few comprehension questions:

Adding "always" and "sensor" would get up to ~99% of values

Would the two answers always and sensor generally replace yes? Or are there other variants that are not covered by this?

The UI might present the options above when asking that, for a question like "Does this crossing have traffic lights?" with answers of "No lights at all", "Yes, pedestrians must wait for the lights", "Yes, pedestrians push a button to trigger flashing lights", "Yes, flashing pedestrian lights are always on", etc.

I would say that this needs its own quest, as I would advocate not activating this quest in the DACH region at least.

Which crosswalks do you use the flashing light for? On all or could you restrict it to only highway=crossing + crossing=uncontrolled/marked or even with crossing:signals=yes?

[HolgerJeromin]

I find the proposed question confusing

Does this crossing have flashing lights for pedestrians?

My initial thought was: The target audience for the lights are the pedestrian. Perhaps because I rarely have seen them (in western europe).

Suggestion:

Does this crossing have flashing lights to warn about pedestrians?

[westnordost]

Some traffic lights in Hamburg have flashing lights, but they are for the car drivers that turn right, to warn them that pedestrians have the walk signal at the same time. They are not for pedestrians.

E.g.

https://www.google.de/maps/@53.5733889,9.9489877,3a,22.9y,35.28h,91.93t/data=!3m7!1e1!3m5!1sSt5cxQtb46oocrMpKH54SA!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-1.9336369002782732%26panoid%3DSt5cxQtb46oocrMpKH54SA%26yaw%3D35.28412017465697!7i16384!8i8192?coh=205410&entry=ttu&g_ep=EgoyMDI0MDkwOC4wIKXMDSoASAFQAw%3D%3D

[mnalis]

I too am worried about "💤 Not an overwhelming percentage of quests have the same answer (No spam)".

When you @knkski say "These crossings are common around me in the US", do you mean they are common in your neighborhood / quarter, in your city, in your state, or in whole of U.S.A. ?

Because, generally, it would be best if quest could be applied to whole world, but quests which are specific just for some country (or just for some State in case of USA) are also possible, but no finer granulation is available.

So, for example, if the quest would be useful in say Portland, but spammy in rest of the Oregon, it would be problematic to include it. (as it would confuse/annoy more users than it would help).

In Croatia, flashing_lights are quite rare, usually only found on busier & more complex intersections, where crossing=traffic_signals have failed to prevent repeated pedestrian injuries/deaths.
Also they could only be described as flashing_lights=yes as they usually fit neither always nor sensor (they are instead automatically synchronized with crossing=traffic_signals, which are in turn mostly based on timer, but sometimes take into account button_operated=yes requests too)

And yes, as noted above, flashing_lights=yes here are "to warn car drivers of possibility of unseen pedestrians", and not "for pedestrians" (crossing=traffic_signals are for pedestrians instead, to let them know when it is safe to cross).

[knkski]

I tracked down exactly what they're called, Rectangular Rapid Flashing Beacons (RRFB):

https://highways.dot.gov/safety/proven-safety-countermeasures/rectangular-rapid-flashing-beacons-rrfb

Broad approval was granted in 2018 to start using these by the US DOT FHA, which mentions usage in Florida. I've noticed these installed more frequently around me in Minnesota as well, particularly as more intersections are being replaced with roundabouts, or with larger construction projects in general.

On to the questions:

Would the two answers always and sensor generally replace yes? Or are there other variants that are not covered by this?

Here's the snippet from the first link:

The flashing pattern can be activated with pushbuttons or passive (e.g., video or infrared) pedestrian detection, and should be unlit when not activated.

I don't recall having seen any that would be considered always, and the official recommendation is to not do that. I would say that yes would not be used, unless you couldn't determine if it was button or sensor for some reason.

Which crosswalks do you use the flashing light for?

As far as I've seen, these are used exclusively at crossings without stop signs or vehicular traffic signals. Pedestrian traffic signals, when they coexist with vehicular traffic signals, are of the sort that tell pedestrians when they are allowed to cross. RRFBs, in contrast, are put in where pedestrians always have priority whenever they want to cross, and the flashing lights are to inform traffic that they're crossing.

Does this crossing have flashing lights to warn about pedestrians?

Sure, that sounds good. For clarity's sake, these lights are warning traffic that a pedestrian is crossing, as opposed to the lights informing pedestrians when crossing is allowed.

When you @knkski say "These crossings are common around me in the US", do you mean they are common in your neighborhood / quarter, in your city, in your state, or in whole of U.S.A. ?

As noted above, I think the range here is US-wide. The OSM wiki notes them in Portland, I've seen them in Minnesota, and the approval process was based on installing them in Florida, which spans from coast to coast.

Let me know if there's any more questions and I'll answer as best I can. If this quest gets added, this PDF from the US DOT FHA has an icon that might work for the app:

[mnalis]

As noted above, I think the range here is US-wide. The OSM wiki notes them in Portland, I've seen them in Minnesota, and the approval process was based on installing them in Florida, which spans from coast to coast.

Could you estimate which percentage of all¹ of Minnesotan² pedestrian crossings would have those flashing lights? 90%? 50%? 10%? 1%?

Footnotes

1. i.e. both those with traffic signs and those with just markings on the road ↩

2. which I assume you're most familiar with ↩

[knkski]

It's difficult for me to estimate. These aren't used on quiet residential streets, so simply querying crossing=marked + highway=crossing pulls up too many extra nodes. These also aren't going to be used where there's already traffic lights for vehicles. They're going to be found primarily when crossing busy roads where there aren't nearby traffic lights (i.e. when crossing stroads). Maybe turbo overpass has a way to query those sorts of situations?

Here's an example of one. Here's an example of what would be useful when thinking about the total fraction. That crossing has the yellow diamond pedestrian crossing sign, but does not have the flashing lights. Out of crossings that have the yellow diamond pedestrian crossing sign, I would guess that RRFBs are 10% and rising in the metro area. I'm not a city planner, but it seems like it's the new thing whenever new construction is done to add them in.

You won't see these without marked crossings, so a useful filter would be "if crossing isn't marked, don't ask", "if crossing has vehicular traffic signals, don't ask", and "if crossing doesn't have tactile pavement markers, dont ask". The last one isn't actually a requirement, but I would be surprised to see one without tactile pavement markers, since these are relatively new and only put in where safety is a concern.

[mnalis]

They're going to be found primarily when crossing busy roads where there aren't nearby traffic lights (i.e. when crossing stroads). Maybe turbo overpass has a way to query those sorts of situations?

Uh, probably, there is around() function in overpass turbo, but I'm not that good with it. Bigger question is how to identify "busy roads" / "stroads" by OSM tagging alone. Are highway=residential considered non-busy (and thus unlikely to have flashing_lights), or are they more often busy "stroads"?

Out of crossings that have the yellow diamond pedestrian crossing sign, I would guess that RRFBs are 10% and rising in the metro area

Hmmm, and how many of all pedestrians crossings would you say have that "yellow diamond pedestrian crossing sign" ?

You won't see these without marked crossings, so a useful filter would be "if crossing isn't marked, don't ask",

OK, limiting the quest to only crossing:markings=yes (or other positive value) would make sense to me.

"if crossing has vehicular traffic signals, don't ask",

Huh, interesting. In my little part of the Europe, majority of flashing_lights are where there are vehicular traffic signals (and most often pedestrian traffic signals too!)

and "if crossing doesn't have tactile pavement markers, dont ask". The last one isn't actually a requirement, but I would be surprised to see one without tactile pavement markers,

Well, anything that can reduce the unnecessary asking of the quest would help; even if it results in some false positives (i.e. not asking a quest rarely when it could've been asked, is preferred to asking the quest all the time when answer would be "no" in majority of them)

[davidpnewton]

In the UK the only crossings which have this sort of thing are zebra and parallel crossings, ie marked crossings that don't have traffic signal control. Here it's the eponymous Belisha beacons that fulfil the function: the flashing orange lights on top of the black and white stripey poles. Those are to make the crossings more visible to vehicular traffic.

[knkski]

Are highway=residential considered non-busy

Yeah, based on a quick informal survey, roads marked highway=residential are very unlikely to have these (i.e. I didn't find any, and don't recall having seen any). I can find them on highway=secondary, highway=tertiary, and highway=service. Here's a case where the RRFBs are installed at the intersection of highway=tertiary and highway=residential. The highway=residential road has stop signs, but the highway=tertiary road doesn't, which is probably why the RRFBs were installed.

The highway=service usage is mostly for areas like parking lots near malls. I also found a usage of crossing a highway=unclassified, but that's probably just incompletely labeled.

Hmmm, and how many of all pedestrians crossings would you say have that "yellow diamond pedestrian crossing sign" ?

A lot of pedestrian crossings across anything other than highway=residential and not at a traffic signal have some sort of "pedestrian crossing" marking. Probably a large majority, based off of memory and a quick survey.

[westnordost]

I updated the starter post with the suggestions and info from this thread.

I also asked in the Slack OSM US chat whether it can be further narrowed down on which kind of roads/crossings they are most likely to be found.

[1ec5]

There was a bit of back-and-forth in the Slack discussion, because in the U.S. there can be multiple kinds of flashing lights at or near crosswalks:

• Rectangular rapid flashing beacon (RRFB) – tagged as flashing_lights=yes
• LEDs embedded in a sign or the roadway – tagged as flashing_lights=yes
• Pedestrian hybrid beacon (“HAWK”) – starting to replace some RRFBs, tagged as crossing_ref=hawk
• Intersection control beacon – tagged as either traffic_signals=blinker or flashing_lights=yes

At least under federal law (which may vary slightly from state to state), RRFBs may only be attached to one of these signs:

Unfortunately, we haven’t been systematically mapping these signs using traffic_sign=* or even tagging their presence using crossing:signed=yes. All we know is that these signs are installed at unsignalized crosswalks mid-block, across the street that has the right of way at a two-way stop (highway=priority), or at a roundabout or slip lane (link road). As a data point, the Maryland State Highway Administration maintains 16,933 non-intersection crosswalks along state-maintained roads, featuring 8,784 signs of the type that are eligible for RRFBs.

The other strict requirement is that an RRFB can’t be installed at a crosswalk controlled by a stop sign, yield sign, traffic lights, or a HAWK beacon. There is an exception for yield signs at approaches to a roundabout and at slip lanes. In other words, it can only be installed at one of the crosswalks that meets the criterion above. Accurately identifying all the eligible crosswalks will be very hard because users haven’t been answering the quest proposed in #4934.

A more conservative approach might be to only enable the quest for unsignalized mid-block crosswalks to begin with: a highway=crossing that isn’t anywhere near an intersection, isn’t anywhere near a highway=traffic_signals, and also isn’t tagged as crossing_ref=hawk. Excluding highway=residential/unclassified/service would be a good idea too, because there will rarely be enough traffic volume to justify special safety measures.

This approach will miss the many RRFBs at crosswalks across two-way stops, but at least you can be pretty sure there’s a sign that could have an RRFB or embedded LED. So even if it happens to be a neighborhood where the authorities haven’t shelled out the $10,000 to install a single RRFB, at least any spamminess won’t come as a surprise.

I don’t think it’s going to be possible to predict a percentage of mid-block crosswalks that will actually have RRFBs. It will be virtually all of them in some jurisdictions and virtually none of them in others, in part because this device was only formally introduced in 2008 under interim approval. That makes it relatively new among pedestrian safety devices. But again, nothing surprising – the presence of crosswalk markings is similarly uneven across the country.

Embedded LEDs are also quite new. They can be embedded not only in the crosswalk signs above but also in stop signs and even in the crosswalk marking itself. The LEDs embedded in stop signs are also flashing_lights=yes; however, I think this tag would be applied to the highway=stop node and any traffic_sign=* node, but not the highway=crossing node.

In my little part of the Europe, majority of flashing_lights are where there are vehicular traffic signals (and most often pedestrian traffic signals too!)

Yes, I’ve seen that configuration plenty in Europe. That configuration never occurs in the U.S. We only use beacons in the absence of vehicular traffic signals.

[westnordost]

That's a lot of information, thank you for this thorough and deep research @1ec5 !

One day, @1ec5 , one day I will get you to contribute code, too!!1 - so your input isn't destined to sit around here for an unspecified amount of time waiting to be processed by someone else but is directly cast into code. StreetComplete is really far too Europe-focus and part of the reason for that is surely because ~all developers are from Europe.

In the meantime, in respect to this quest proposal, could you summarize¹ what you'd think would be a reasonable element filter and wording? (Yes, it is possible in StreetComplete to look for nodes not within X meters of an intersection of certain roads)
Also, note that we tag flashing_lights=yes, they don't have to be RRFBs.

---

¹ the longer a ticket becomes, the less likely it becomes that someone else is going to pick it up to work on it because there is too much to dig into. So to add a summary at the end is a good way to conclude the discussion and make the ticket actionable (again)

[1ec5]

Sorry for the infodump – it was too much for Slack, so I put it here. Maybe the forum would be a better place to take it next time.

This is the simplest conservative criteria I can come up with for a likely crosswalk sign that might have a flashing light:

• The highway=crossing node is tagged crossing:markings=yes or similar; and
• The highway=crossing node is not tagged crossing:signals=yes or similar; and
• The highway=crossing node is not tagged crossing_ref=hawk; and
• Either:
  • The highway=crossing node is part of a highway=trunk/primary/secondary/tertiary way; and
  • The highway=crossing node is at least 30 meters (at least 100 feet) from the nearest intersection with another highway=motorway/motorway_link/…/tertiary/tertiary_link way; and
  • The highway=crossing node is at least 30 meters (at least 100 feet) from the nearest highway=stop/give_way node; and
  • The highway=crossing node is at least 90 meters (at least 300 feet) from the nearest highway=traffic_signals node;
• Or:
  • The highway=crossing node is part of a highway=trunk/primary/secondary/tertiary way; and
  • The highway=crossing node is at most 30 meters (at most 100 feet) from a junction=uncontrolled node;
• Or:
  • The highway=crossing node is part of a highway=motorway/motorway_link/…/tertiary/tertiary_link way that is tagged oneway=yes and connected to a junction=roundabout way.

I’d appreciate a gut-check on any of these criteria. Unfortunately, I’m struggling to come up with a simpler, more reliable heuristic. Maybe it’s because asking about flashing lights is a bit premature. We’d be in a much better spot if we were already mapping the presence of signs, but I’m surprised that crossing:signed=* is only used 51 times globally. I guess there isn’t a well-established tag because other countries just assume that any crossing=marked has both “horizontal” and “vertical signaling”, as they say in Europe. We’d also be able to make a more informed guess as to crosswalk signage if we could distinguish between two- and four-way stops: #4934.

[jarek]

This is the simplest conservative criteria I can come up with for a likely crosswalk sign that might have a flashing light:

For what it's worth, I've been looking at tagging for crossings with flashing lights in Ontario and these criteria would also cover most of them there 👍

Ontario's prescribed distances from signals/stop signs are similar; they can be waived or ignored in some cases, but are probably good enough for more casual street-side surveys.

[BalooUriza]

I tracked down exactly what they're called, Rectangular Rapid Flashing Beacons (RRFB):

https://highways.dot.gov/safety/proven-safety-countermeasures/rectangular-rapid-flashing-beacons-rrfb

These aren't the only kind. Traditional single-aspect flashing yellow ball lights are also (possibly even more) common in North America. Belisha beacons on zebra crossings would be an example in the UK and many former commonwealths. Parts of the US also use backlit pedestrian signs, some of which either flash permanently or flash when a pedestrian requests it.

In any case, they're a pretty good crosswalk to avoid or only use as a last resort as a pedestrian from my experience.