NDOT changing many "Prepare To STOP When Flashing" installations

[gonealookin]

In my area, NDOT will be removing a number of the "Prepare To STOP When Flashing" overhead sign installations in the next month or so, replacing them with continuous flashers or simple static "Signal Ahead" signs.  This is apparently as a result of studies that say "Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

Known as advance signal warning systems, the yellow signs are placed ahead of certain traffic signals to draw attention to the signal ahead. Some advance signal warning signs contain lights which continuously flash. Others begin flashing when the traffic signal ahead readies to turn yellow and red, allowing drivers time to prepare to stop in advance of the signal. This can lead drivers to unsafely speed up to "beat the light," potentially leading to crashes.

https://www.nevadadot.com/Home/Components/News/News/6590/395

The installations being removed are mostly on 4-lane highways with speed limits between 45-55 mph.

[roadfro]

In my area, NDOT will be removing a number of the "Prepare To STOP When Flashing" overhead sign installations in the next month or so, replacing them with continuous flashers or simple static "Signal Ahead" signs.  This is apparently as a result of studies that say "Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

Known as advance signal warning systems, the yellow signs are placed ahead of certain traffic signals to draw attention to the signal ahead. Some advance signal warning signs contain lights which continuously flash. Others begin flashing when the traffic signal ahead readies to turn yellow and red, allowing drivers time to prepare to stop in advance of the signal. This can lead drivers to unsafely speed up to "beat the light," potentially leading to crashes.

https://www.nevadadot.com/Home/Components/News/News/6590/395

The installations being removed are mostly on 4-lane highways with speed limits between 45-55 mph.

I had forgotten about this study; thanks for pointing it out.

It's true the "prepare to stop when flashing" signs do prompt people to speed up to beat the light. And I do think some use of these has been a bit unwarranted at times (many of the ones along Pyramid Highway are being removed or converted to static/passive systems).

I've sometimes thought that the active systems should instead flash only when the signal is already red or on onset of yellow, instead of when the signal is preparing to change from green to yellow–seems like that would lessen the "beat the light" mentality.

[Kniwt]

"Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

But pedestrian countdown signals often perform the same function for motorists, and with much more accuracy. (Excluding the cases where the green duration is longer than the walk duration.) I don't recall seeing ped signals along US 395 near Minden, but I suspect Pyramid Highway has lots of them.

[roadfro]

"Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

But pedestrian countdown signals often perform the same function for motorists, and with much more accuracy. (Excluding the cases where the green duration is longer than the walk duration.) I don't recall seeing ped signals along US 395 near Minden, but I suspect Pyramid Highway has lots of them.

True, but the pedestrian countdown signals are at the intersection itself and off to the side (not always visible depending on traffic), so the amount of time and distance that they function as a "step on it" indicator to drivers is relatively small. Compare to the advance signal warning system installations which are often several hundred feet upstream of a signal and designed to be seen by all drivers, so they can function as a "step on it" indicator from a much further distance.

There aren't ped signals on US 395 north of Minden since that's rural divided highway. But there are ped signals along most of the Pyramid Highway locations listed since these are all still fairly urban (despite that there isn't much ped activity out there).

[Plutonic Panda]

"Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

But pedestrian countdown signals often perform the same function for motorists, and with much more accuracy. (Excluding the cases where the green duration is longer than the walk duration.) I don't recall seeing ped signals along US 395 near Minden, but I suspect Pyramid Highway has lots of them.

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

[stevashe]

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

Taiwan has them, but they're displayed during red lights and count down to when it will turn green, not the other way around.
https://goo.gl/maps/4DeDMhP3Q9z9Z5sa9

[compdude787]

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

Taiwan has them, but they're displayed during red lights and count down to when it will turn green, not the other way around.
https://goo.gl/maps/4DeDMhP3Q9z9Z5sa9

That's actually a great idea!

[pderocco]

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

Taiwan has them, but they're displayed during red lights and count down to when it will turn green, not the other way around.
https://goo.gl/maps/4DeDMhP3Q9z9Z5sa9

That's actually a great idea!

Don'tcha just look at the WALK/DON'T WALK signal going the other way?

[stevashe]

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

Taiwan has them, but they're displayed during red lights and count down to when it will turn green, not the other way around.
https://goo.gl/maps/4DeDMhP3Q9z9Z5sa9

That's actually a great idea!

Don'tcha just look at the WALK/DON'T WALK signal going the other way?

You can't see that unless you're the first, maybe second, car in line though.

[skluth]

I could be wrong but I seem to recall a country that actually has countdown timers for motorists at signalized intersections.

Taiwan has them, but they're displayed during red lights and count down to when it will turn green, not the other way around.
https://goo.gl/maps/4DeDMhP3Q9z9Z5sa9

That's actually a great idea!

Don'tcha just look at the WALK/DON'T WALK signal going the other way?

You can't see that unless you're the first, maybe second, car in line though.

I get what pderocco is talking about because I've done it as well. Unfortunately, it doesn't work at a lot of intersections. I walk a lot locally for exercise. Many Palm Springs intersections will finish counting down and then display DON'T WALK for several seconds before the associated light turns yellow and it's 3-4 seconds before it turns red. They may also give pedestrians a WALK light for a couple seconds before the through street gets their green. (Just observed this again today waiting to cross at Mesquite and Farrell.) I will do it when I'm familiar with how the light works, but I won't even bother if I'm somewhere I don't know well.

[roadfro]

Mod Note: Split the above posts out of the general "Nevada" thread 3/12/22 since this might generate more threaded discussion.


For those interested, here is NDOT's website about their study and statewide changes to advanced signal warning systems: https://www.nvsafesignals.com/

And from a recent article from the RGJ, some people think the removal of some of the active warning systems in the Reno area, especially along SR 445/Pyramid Highway, amount to a waste of taxpayer dollars.

Taking down traffic warning signals around Reno area called "˜expensive and unnecessary', Reno Gazette-Journal, 3/11/2022

Advance warning traffic signals — those lights that flash yellow when an upcoming signal is going to change to red — will start to be removed at 10 locations around the Reno area beginning Monday.

The Nevada Department of Transportation says getting rid of the warning signals conforms to new traffic recommendations and that they may be dangerous because some drivers speed up when the lights begin flashing.

Washoe County Commissioner Vaughn Hartung — whose district contains most of the warning signals coming down — disagrees.

"Removing the signals is expensive and unnecessary,"  he said in a call with the RGJ. "I don't believe removing them will make the Pyramid Highway corridor safer."  

NDOT sent contract details to the RGJ showing the cost range of the project at $430,000 to $515,000.
<...>
Removal of advance warning signals will happen along Pyramid Highway, Veterans Parkway and Mt. Rose Highway.

"These changes are being made to bring our system into alignment with updated national safety standards — Manual on Uniform Traffic Control Devices — which will enhance traffic uniformity and safety for all,"  she said in an email to the RGJ.

Another reason is to reduce the potential of red-light running.

"A recent study at a Pyramid Highway intersection shows that most drivers sped up after advance signals begin flashing,"  she said. "While not everyone speeds up after the (advance warning) signal, this leads to the conclusion that many drivers are exploiting the advance warning signal to try to beat the light — an unsafe driving practice that could lead to more crashes."
<...>
Hartung said that instead of taking down warning signals, he thinks increasing capacity on Pyramid Highway — such as widening the road — would do more for safety. It's also something that hasn't been done in 30 years despite massive growth, he added.

I've long thought that several of the active warning systems that are in place out on Pyramid Highway were not really warranted to begin with. Many are on straight stretches with no sight distance issues to the signal. So they are very clear indications for drivers to speed up to beat the light...which happens frequently, especially in this stretch where speed limit is already 45 or 55 with higher prevailing speeds.

But at the same time, around half a mil seems like a really large price tag...hopefully that's the statewide figure, and not just the Reno-area changes.

[Plutonic Panda]

Wow I rather thought those were something we should install more of. Not really sure I believe someone who'd see one and then speed up to beat the light wouldn't do it anyways without advanced warning but perhaps there's something subconscious going on.

[hotdogPi]

Wow I rather thought those were something we should install more of. Not really sure I believe someone who'd see one and then speed up to beat the light wouldn't do it anyways without advanced warning but perhaps there's something subconscious going on.

The sign I'm familiar with that says RED Signal Ahead (with RED being electronic) is placed before a vertical curve, which means that drivers see the sign before they see the signal.

https://www.google.com/maps/@42.6242285,-71.2660317,3a,67y,314.57h,88.45t/data=!3m6!1e1!3m4!1sUfSaMVIUVeJWSfTsMrCAoQ!2e0!7i16384!8i8192

[jakeroot]

Have there been any studies on pedestrian countdown timers? In timed areas (esp urban areas with automatic walk), I frequently use pedestrian countdown timers to know whether I will make the light or not.

In British Columbia, "prepare to stop when flashing" (PTSWF) (W-012-xxx) signs are required at all intersections in (I think) 70 km/h+ zones, so they are wildly popular across the province in all sorts of urban, suburban, and rural areas.

[ran4sh]

Interesting that Nevada is doing this. Georgia removed all of its advance warning flashers about 2-3 decades ago (more precisely, Georgia reprogrammed them so that they flash all the time instead of functioning as a way to gauge the upcoming signal indication).

There is research that says a high speed road that trucks are allowed to use, *needs* to have advance warning of traffic signal indications (sometimes called "distant signals"), otherwise, the only safe thing for trucks to do is to slow down to 45-55 mph approaching each and every signal (which causes traffic flow issues when cars expect 65-75 mph traffic).

If NDOT was having issues with drivers trying to beat the yellow, what should have happened was that the advance stop indication (flashing light) should have been adjusted to start a few seconds earlier, instead of removing it entirely.

[kphoger]

Have there been any studies on pedestrian countdown timers? In timed areas (esp urban areas with automatic walk), I frequently use pedestrian countdown timers to know whether I will make the light or not.

I've given up doing that, because I can't memorize which intersections turn yellow when the countdown gets to zero, and which ones turn yellow several seconds later.

[roadfro]

Wow I rather thought those were something we should install more of. Not really sure I believe someone who'd see one and then speed up to beat the light wouldn't do it anyways without advanced warning but perhaps there's something subconscious going on.

In cases like some of the advanced signal warning flashers out on Pyramid Highway with more than adequate sight distance, the activation of PTSWF signs can serve as an early indicator for how to approach the dilemma zone. Say you're approaching a signal with a stale green and you're coming up on the upstream PTSWF sign going the speed limit and it just starts to flash as you pass, you can reasonably deduce that a slight increase in speed will get you through the light before onset of the red indication. With my traffic engineering knowledge, I have done exactly that on a few occasions at some of these Pyramid Highway locations NDOT is planning to remove (and that's not even a part of Reno-Sparks I'm in regularly), so it's not unreasonable to assume others with less knowledge can learn to take advantage of this, especially if they pass by such a setup on their regular commute.

Contrast to approaching a stale green without a PTSWF flasher...you have no way of knowing when the signal will turn, so there's not really anything to prompt you to speed up.

Interesting that Nevada is doing this. Georgia removed all of its advance warning flashers about 2-3 decades ago (more precisely, Georgia reprogrammed them so that they flash all the time instead of functioning as a way to gauge the upcoming signal indication).
<...>
If NDOT was having issues with drivers trying to beat the yellow, what should have happened was that the advance stop indication (flashing light) should have been adjusted to start a few seconds earlier, instead of removing it entirely.

NDOT is removing some in favor of a static "signal ahead" sign, converting others to become "signal ahead" constantly flashing beacons, or keeping a few that are more necessary due to sight distance and queuing issues but re-timing the flash pattern.

I don't know that adjusting the timing pattern to start earlier would have been the right thing to do for all of these. If it starts flashing earlier, you have a "prepare to stop" warning, but ultimately those first several drivers passing when the flashing activates might not actually need to stop...which defeats the purpose.

[zachary_amaryllis]

In my area, NDOT will be removing a number of the "Prepare To STOP When Flashing" overhead sign installations in the next month or so, replacing them with continuous flashers or simple static "Signal Ahead" signs.  This is apparently as a result of studies that say "Yellow light means step on the gas, and the flashing lights mean the signal ahead is about to turn yellow, so step on the gas even harder."

The installations being removed are mostly on 4-lane highways with speed limits between 45-55 mph.

i've seen a few of these along us-50 between pueblo and canon city, and a few on co-115 as you get close to colorado springs. us-50 is speed limit 65 in that area. there may be some intricacy i'm missing with these, but they seem like they're way too close to the intersections. you can certainly see them quite a ways away (it's mostly flattish to rolling hills through there). it's also noteworthy that at every one of those intersections, there's ridiculously long skid marks.

[US 89]

Wow I rather thought those were something we should install more of. Not really sure I believe someone who'd see one and then speed up to beat the light wouldn't do it anyways without advanced warning but perhaps there's something subconscious going on.

In cases like some of the advanced signal warning flashers out on Pyramid Highway with more than adequate sight distance, the activation of PTSWF signs can serve as an early indicator for how to approach the dilemma zone. Say you're approaching a signal with a stale green and you're coming up on the upstream PTSWF sign going the speed limit and it just starts to flash as you pass, you can reasonably deduce that a slight increase in speed will get you through the light before onset of the red indication. With my traffic engineering knowledge, I have done exactly that on a few occasions at some of these Pyramid Highway locations NDOT is planning to remove (and that's not even a part of Reno-Sparks I'm in regularly), so it's not unreasonable to assume others with less knowledge can learn to take advantage of this, especially if they pass by such a setup on their regular commute.

Contrast to approaching a stale green without a PTSWF flasher...you have no way of knowing when the signal will turn, so there's not really anything to prompt you to speed up.

And on high-speed corridors, the yellow lights have to be absurdly long (sometimes over 6 seconds). In my experience, people are more likely to gun it through those yellows simply because they know they have that extra yellow cushion time that doesn't exist at most lights. This means if you do that and you guess the yellow is going to be longer than that actually is, you're potentially running a red light at 70+ mph. That seems far more dangerous to me than the possibility of someone speeding up maybe 5 mph to beat a light after seeing a PTSWF flasher, which at least gives you more time to make a decision than the split second you get once you see the yellow.