Traffic signal

[fwydriver405]

Took a mini-road trip over the past few days and saw some interesting signal configurations:

Meredith NH: I noticed some preemption equipment at this PHB signal. There is also similar equipment in Quincy MA as well. How does preemption work with these signals? Does it simply inhibit the pedestrian phase and/or terminate an in-progress pedestrian phase?

Chelsea MA: This 3-section traffic signal for a right turn slip lane is R-Y-FR, near a drawbridge. Never seen this configuration before and it looks more like a fire signal that you'd normally see on the fire station side and/or side streets.

[mrsman]

Took a mini-road trip over the past few days and saw some interesting signal configurations:

Meredith NH: I noticed some preemption equipment at this PHB signal. There is also similar equipment in Quincy MA as well. How does preemption work with these signals? Does it simply inhibit the pedestrian phase and/or terminate an in-progress pedestrian phase?

Chelsea MA: This 3-section traffic signal for a right turn slip lane is R-Y-FR, near a drawbridge. Never seen this configuration before and it looks more like a fire signal that you'd normally see on the fire station side and/or side streets.

Regarding preemption, it is likely that those HAWK signals get preempted by delaying the pedestrian call.  That is the only phase that would affect emergency vehicles.  If the signal is dark, it should stay dark longer.  If it is already flashing yellow, it can flash yellow a little longer.  Once it goes to solid yellow or solid red it has to remain on that, because a pedestrian will be crossing.  A flashing red also cannot be terminated early, as that is part of the pedestrian clearance phase.  (but then again, traffic can proceed on that phase with a stop)

Correct me if I'm wrong, but if a pedestrian call has been activated, I believe that preemption cannot shorten the pedestrian clearance phase, i.e. the flashing don't walk.  But pedestrian clearance can bring the signal from walk directly to the flashing don't walk phase.

I don't understand the R-Y-FR signal for a drawbridge.  Perhaps they allow a flashing red when the signal opposes cross traffic so that turning traffic will come to a complete stop and yield to any traffic in its way, but a solid red is shown when the drawbridge is up.  IMO, something like this would be better served with a regular R-Y-G signal and then an electronic no right turn sign that lights up when the bridge is out.  This is common at many right turns where the road you are turning from is parallel to a RR crossing.

Los Angeles has a unique application of this type of signal at driveways that are part of a regular intersection, signalled as R-FR-Y.  When I was a kid, these were signaled with a R-FR, but now they have added a yellow phase as well.

Take a look here:

https://www.google.com/maps/@34.0551703,-118.3863072,3a,75y,215.66h,86.18t/data=!3m6!1e1!3m4!1sgDfPl-XyfEivPNanRbJ5Mg!2e0!7i16384!8i8192


Basically, Livonia is a small street that ends at Pico at a T-intersection.  But it's not a pure T, as from the top of the T is a driveway to/from the bank parking lot.  In this manner, a left from Livonia to Pico is given right of way over traffic from the bank heading down Livonia.  When Livionia gets green, bank gets a flashing red and sees a sign to "watch opposing traffic".  Since its a flashing red, the driveway traffic is forced to treat the intersection like a stop sign, even though the main Pico traffic is stopped by a red light.

While something like this may be useful over a small driveway, I don't like the arrangement here.  THe normal traffic pattern should be that both directions get green and that anyone turning left must yield to opposing traffic.

[Amtrakprod]

The R-Y-FR light stays FR until the drawbridge is activated which then it'll go red.


iPhone

[STLmapboy]

Signal in Grand Forks, ND, with a light fixture coming from the pole.

[jakeroot]

Signal in Grand Forks, ND, with a light fixture coming from the pole.

I assume you are referring to the apparent mismatch of the light fixture with the signal mast? I ask because light fixtures coming out of a signal mast is standard procedure in most places, although they are typically more integrated than what's seen here.

[paulthemapguy]

Signal in Grand Forks, ND, with a light fixture coming from the pole.

That looks ...interesting, like it was Frankenstein'd together lol.  Are FYA's commonly used on signals in ND?

[STLmapboy]

Signal in Grand Forks, ND, with a light fixture coming from the pole.

That looks ...interesting, like it was Frankenstein'd together lol.  Are FYA's commonly used on signals in ND?

2017 and onward installs, roughly. It's still majority doghouse.

[STLmapboy]

https://www.google.com/maps/@28.1917119,-82.4657267,3a,16.8y,288.91h,97.2t/data=!3m6!1e1!3m4!1shdVMCY-ub9gqZIp6BnZDQA!2e0!7i16384!8i8192
So close yet so far. In Florida.

[jakeroot]

https://www.google.com/maps/@28.1917119,-82.4657267,3a,16.8y,288.91h,97.2t/data=!3m6!1e1!3m4!1shdVMCY-ub9gqZIp6BnZDQA!2e0!7i16384!8i8192
So close yet so far. In Florida.

I'm more intrigued by how three of the four approaches have all of the primary signals near-side, with the stop lines set back to accommodate for it. Very European.

[STLmapboy]

https://www.google.com/maps/@28.1917119,-82.4657267,3a,16.8y,288.91h,97.2t/data=!3m6!1e1!3m4!1shdVMCY-ub9gqZIp6BnZDQA!2e0!7i16384!8i8192
So close yet so far. In Florida.

I'm more intrigued by how three of the four approaches have all of the primary signals near-side, with the stop lines set back to accommodate for it. Very European.

That seems to be somewhat common at larger intersections in the Sunshine State. Anyone have any more examples?

[Amtrakprod]

Anyone else have tons of lights with a symbol text hybrid.




iPhone

[Big John]

^^ Those are becoming more as the 2000 MUTCD allowed symbol-only pedestrian signals allowing existing word signs to stay in place.

Also rare is 2 pedestrian signals on the same quadrant pointing the same way.

[US 89]

Anyone else have tons of lights with a symbol text hybrid.

Logan, Utah has a handful, but the symbol and text are switched there:



Looks like this was about to be replaced by a new mast-arm signal, which almost certainly means those are gone by now. As far as I know, unless there's one at some minor intersection in Salt Lake, Logan is the only place in Utah to still have text pedestrian signals of any kind.

[Amtrakprod]

Here's a weirder example in Davis square MA:


https://youtu.be/sBoNcPIa1v8


iPhone

[CardInLex]

A select number of traffic signals in Lexington, KY on Nicholasville Rd (US 27) feature a small blue indication in the rear of the signal heads. This blue light indicates that that head is red. You can see it illuminated here on the opposing left turn signal:

https://goo.gl/maps/5EbRfbwJBccyQJVHA

(If link doesn't load properly look at the backside of the southbound signal heads at the Reynolds Rd intersection).

[RestrictOnTheHanger]

I saw those in Florida. I think theyre nicknamed snitch lights since cops can post up and write tickets easier

[UCFKnights]

I saw those in Florida. I think theyre nicknamed snitch lights since cops can post up and write tickets easier

They also are usually mounted on the top of the signal around here so it can be seen in all directions unlike that Kentucky one:
https://www.google.com/maps/@28.6063154,-81.1986321,3a,27.8y,21.31h,102.3t/data=!3m6!1e1!3m4!1svbcHge_ZEHgKZG1kkQqBow!2e0!7i16384!8i8192

They're very widespread on most university campuses throughout the state.

[SignBridge]

That light in the Florida photo might be there to indicate when the signal has been pre-empted by an approaching emergency vehicle.

[UCFKnights]

That light in the Florida photo might be there to indicate when the signal has been pre-empted by an approaching emergency vehicle.

It does not, they go on and off with the red light right below it always.

[plain]

The blue lights on the traffic signals are definitely there for the cops to use. It makes it easier for them to see which signal is red, thus making it easier to catch red light runners. Newport News, VA have been using these at certain intersections for about five years now.

To me they're an alternate to using red light cameras.

[HTM Duke]

I saw those in Florida. I think theyre nicknamed snitch lights since cops can post up and write tickets easier

I've always referred to them as "rat lights" (as in the light will rat you out to an officer nearby if you run the red), but don't remember where I exactly picked up that name.  And yes, they're all over the major intersections in Pinellas County, but for the most part seem to be attached to the underside of signals.  However, a couple of times I've seen these lights attached to the back of school zone signs that include flashers, and the light on the back would flash along with the lights on the front of the sign when the school zone was active.

[fwydriver405]

I saw those in Florida. I think theyre nicknamed snitch lights since cops can post up and write tickets easier

I've always referred to them as "rat lights" (as in the light will rat you out to an officer nearby if you run the red), but don't remember where I exactly picked up that name.  And yes, they're all over the major intersections in Pinellas County, but for the most part seem to be attached to the underside of signals.  However, a couple of times I've seen these lights attached to the back of school zone signs that include flashers, and the light on the back would flash along with the lights on the front of the sign when the school zone was active.

Are the blue lights mentioned above similar to these lights on the back on ramp meter signals in California?

[CJResotko]

https://www.google.com/maps/@43.0798294,-96.1755213,3a,16.9y,285.13h,89.1t/data=!3m6!1e1!3m4!1s0xVoVtwPyYG1R4ypENAPcg!2e0!7i13312!8i6656
I found this intersection in Sioux Center, Iowa, where on the old worded ped signals, the WALK is on top and the DON'T WALK is on the bottom. Have never seen one like this until now.

[HTM Duke]

I saw those in Florida. I think theyre nicknamed snitch lights since cops can post up and write tickets easier

I've always referred to them as "rat lights" (as in the light will rat you out to an officer nearby if you run the red), but don't remember where I exactly picked up that name.  And yes, they're all over the major intersections in Pinellas County, but for the most part seem to be attached to the underside of signals.  However, a couple of times I've seen these lights attached to the back of school zone signs that include flashers, and the light on the back would flash along with the lights on the front of the sign when the school zone was active.

Are the blue lights mentioned above similar to these lights on the back on ramp meter signals in California?

In terms of function, yes; design, not so much.  These lights were installed to inform police that the light was red (save the school zone example I mentioned), but vary in terms of color and placement.  In Newport News, they're blue and on top, while in Pinellas, they're white and on bottom.

[STLmapboy]

Mirror, mirror, on the wall, is there no end to the redundancy at all?

Yes, that is 5 side mounts and one overhead signal.