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National Boards => General Highway Talk => Traffic Control => Topic started by: tradephoric on December 31, 2013, 01:46:26 PM

Title: Signals that turn red when a speeding car approaches
Post by: tradephoric on December 31, 2013, 01:46:26 PM
This is different than a red light camera! 

The idea is if a vehicle is traveling above the speed limit, the signal will automatically turn red before the speeder can make it through the light.  The traffic signal is essentially used as a traffic calming device.   



Here's an example on Porter Street in Washington D.C. (the sign states "Signal turns red when speeding"):
https://maps.google.com/?ll=38.937085,-77.06509&spn=0.001177,0.001725&t=h&z=19&layer=c&cbll=38.937182,-77.065153&panoid=DaBoONjfwPfholq6ws7ulg&cbp=12,128.95,,0,3.22 (https://maps.google.com/?ll=38.937085,-77.06509&spn=0.001177,0.001725&t=h&z=19&layer=c&cbll=38.937182,-77.065153&panoid=DaBoONjfwPfholq6ws7ulg&cbp=12,128.95,,0,3.22)
Title: Re: Signals that turn red when a speeding car approaches
Post by: hotdogPi on December 31, 2013, 02:18:45 PM
Does that mean it just skips the yellow?
Title: Re: Signals that turn red when a speeding car approaches
Post by: 1995hoo on December 31, 2013, 02:19:25 PM
There's one of those on southbound Taylor Run Parkway in Alexandria, Virginia. The speed limit is 25 and I, of course, had to test it out to see if it would really turn red. It did.

In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out) and has the same wording as the one the OP cites except it uses the word "red" instead of the red circle icon (Takumi memorably referred to that as "No Turn on Japan" in another context). The traffic light is visible in the distance. You'd have to be going insanely fast to get through before it turns red, fast enough that if you were caught you'd probably face a license suspension. The light is annoying as it's placed mid-block. I assume the city would say it's there to protect pedestrians going to the park on the east side of the street.

http://goo.gl/maps/piMzb
Title: Re: Signals that turn red when a speeding car approaches
Post by: DaBigE on December 31, 2013, 02:27:51 PM
This sounds like an accident waiting to happen. About as bad as using STOP signs to curb speeding or uncoordinated signals. Interesting idea, but I'd rather not encourage more unnecessary red lights.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Big John on December 31, 2013, 02:42:54 PM
And with narrow sidewalks and no ADA sidewalk ramps either.
Title: Re: Signals that turn red when a speeding car approaches
Post by: oscar on December 31, 2013, 04:08:01 PM
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out)
http://goo.gl/maps/piMzb

I think it's an accidental (but all too common) result of deliberately blurring out some details to protect people it catches in embarrassing places or positions.  Blurring out faces of people peeing in the gutter, OK.  Blurring out license plate numbers, I can see as well, to protect people who might be cruising through bad neighborhoods for drugs or hookers, or even more respectable places on the "cheating side of town".  But I can imagine the same process blurring some road signs too.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Alex4897 on December 31, 2013, 04:39:46 PM
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out)

https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16 (https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16)

Ta-daaa
Title: Re: Signals that turn red when a speeding car approaches
Post by: 1995hoo on December 31, 2013, 04:56:32 PM
Quote from: Alex4897 on December 31, 2013, 04:39:46 PM
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out)

https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16 (https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16)

Ta-daaa

Yeah, but it's not any more legible in that view (at least, not on my iPad it's not).
Title: Re: Signals that turn red when a speeding car approaches
Post by: Alex4897 on December 31, 2013, 04:59:31 PM
Quote from: 1995hoo on December 31, 2013, 04:56:32 PM
Quote from: Alex4897 on December 31, 2013, 04:39:46 PM
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out)

https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16 (https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16)

Ta-daaa

Yeah, but it's not any more legible in that view (at least, not on my iPad it's not).

It's a lot more legible on my computer
Title: Re: Signals that turn red when a speeding car approaches
Post by: hotdogPi on December 31, 2013, 04:59:48 PM
Quote from: 1995hoo on December 31, 2013, 04:56:32 PM
Quote from: Alex4897 on December 31, 2013, 04:39:46 PM
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
In the Street View image, the warning sign is to the right (I don't know why it's fuzzed out)

https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16 (https://maps.google.com/?ll=38.810486,-77.075229&spn=0.015383,0.033023&t=m&layer=c&cbll=38.810559,-77.075241&panoid=mFMxfX1lNAeJ7B-iZOJihA&cbp=12,208.38,,1,3.04&z=16)

Ta-daaa

Yeah, but it's not any more legible in that view (at least, not on my iPad it's not).

Once I zoom in to a closer view, it works.
Title: Re: Signals that turn red when a speeding car approaches
Post by: agentsteel53 on December 31, 2013, 05:38:18 PM
that would only be a reasonable device if it turned back green once I went back below the speed limit.

otherwise, welcome to the sound of screeching brakes, which is really what traffic calming is all about.
Title: Re: Signals that turn red when a speeding car approaches
Post by: corco on December 31, 2013, 05:43:40 PM
Is there not a serious personal safety issue here? If im a relatively amateur theft ring, and i see a car i want to rob in the middle of the night, and I see that car  going the speed limit, I can speed up behind them, trigger a light change, and then have my buddy with a gun wait on foot at the intersection, run out, and carjack. This is much easier to pull off when we know exactly where and when the light is going to change.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Jardine on December 31, 2013, 10:01:40 PM
Cohort can already press the pedestrian button . . .

:wow:
Title: Re: Signals that turn red when a speeding car approaches
Post by: DaBigE on December 31, 2013, 10:39:09 PM
Quote from: Jardine on December 31, 2013, 10:01:40 PM
Cohort can already press the pedestrian button . . .

:wow:

Pressing button only places a call. Unless you know the exact timing schedule and precisely where in the cycle the signal is, there is no guarantee it will work outside of a peak travel period (and during the peak, you'll obviously have quite a few witnesses). As I understand it, this system changes the signal on a per car basis.
Title: Re: Signals that turn red when a speeding car approaches
Post by: hbelkins on December 31, 2013, 10:56:43 PM
Unless the light for cross-street traffic stays red and doesn't turn green, this is an accident waiting to happen. The speeding car is quite likely to blow through the red light that's triggered by his speeding, and if the cross-traffic light turns green, cars sitting there are going to go and get clobbered by the speeding vehicle.

I'd think a speed camera would be a lot less dangerous.
Title: Re: Signals that turn red when a speeding car approaches
Post by: 1995hoo on January 01, 2014, 12:30:39 AM
Quote from: hbelkins on December 31, 2013, 10:56:43 PM
Unless the light for cross-street traffic stays red and doesn't turn green, this is an accident waiting to happen. The speeding car is quite likely to blow through the red light that's triggered by his speeding, and if the cross-traffic light turns green, cars sitting there are going to go and get clobbered by the speeding vehicle.

I'd think a speed camera would be a lot less dangerous.

In the example I posted there is no cross street, which makes the light all the more annoying.
Title: Re: Signals that turn red when a speeding car approaches
Post by: NE2 on January 01, 2014, 01:10:37 AM
Quote from: hbelkins on December 31, 2013, 10:56:43 PM
Unless the light for cross-street traffic stays red and doesn't turn green, this is an accident waiting to happen. The speeding car is quite likely to blow through the red light that's triggered by his speeding, and if the cross-traffic light turns green, cars sitting there are going to go and get clobbered by the speeding vehicle.

Learn to read.
Quote from: 1995hoo on December 31, 2013, 02:19:25 PM
The traffic light is visible in the distance. You'd have to be going insanely fast to get through before it turns red, fast enough that if you were caught you'd probably face a license suspension.
Title: Re: Signals that turn red when a speeding car approaches
Post by: froggie on January 01, 2014, 09:32:21 AM
QuoteThis sounds like an accident waiting to happen. About as bad as using STOP signs to curb speeding or uncoordinated signals. Interesting idea, but I'd rather not encourage more unnecessary red lights.

As I recall, the DC example was implemented before the city started on their speed camera campaign.  Also, the simple solution (and the way to avoid the "unnecessary red light") is just to not speed.

Quoteotherwise, welcome to the sound of screeching brakes, which is really what traffic calming is all about.

Only if you don't know how to properly drive or properly use your brakes.  Admittedly, that's most US drivers.
Title: Re: Signals that turn red when a speeding car approaches
Post by: DaBigE on January 01, 2014, 01:50:33 PM
The question I have is how far above the speed limit does one typically have to go to trigger the red light? 2 mph? 5 mph? I routinely see squads going 10 over on routine patrol--I'd LMAO if I saw one of those squads trigger a light.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Brandon on January 01, 2014, 01:59:59 PM
Quote from: froggie on January 01, 2014, 09:32:21 AM
QuoteThis sounds like an accident waiting to happen. About as bad as using STOP signs to curb speeding or uncoordinated signals. Interesting idea, but I'd rather not encourage more unnecessary red lights.

As I recall, the DC example was implemented before the city started on their speed camera campaign.  Also, the simple solution (and the way to avoid the "unnecessary red light") is just to not speed.

A far better solution would be to simply time all the signals for the speed limit.
Title: Re: Signals that turn red when a speeding car approaches
Post by: hbelkins on January 01, 2014, 05:05:41 PM
I didn't click the link to see the intersection in question. So sue me.
Title: Re: Signals that turn red when a speeding car approaches
Post by: 1995hoo on January 01, 2014, 05:15:54 PM
Quote from: Brandon on January 01, 2014, 01:59:59 PM
Quote from: froggie on January 01, 2014, 09:32:21 AM
QuoteThis sounds like an accident waiting to happen. About as bad as using STOP signs to curb speeding or uncoordinated signals. Interesting idea, but I'd rather not encourage more unnecessary red lights.

As I recall, the DC example was implemented before the city started on their speed camera campaign.  Also, the simple solution (and the way to avoid the "unnecessary red light") is just to not speed.

A far better solution would be to simply time all the signals for the speed limit.

I've encountered a number of roads in DC where the signals are timed such that if you do the speed limit, you have to stop at every one of them.
Title: Re: Signals that turn red when a speeding car approaches
Post by: hotdogPi on January 01, 2014, 05:19:55 PM
There was a sign (it was white on green!) in Philadelphia that said "signals set for 20 mph".
Title: Re: Signals that turn red when a speeding car approaches
Post by: agentsteel53 on January 01, 2014, 05:20:27 PM
Quote from: Brandon on January 01, 2014, 01:59:59 PM

A far better solution would be to simply time all the signals for the speed limit.

I think Klamath Falls OR still has its main drag timed, complete with signs on every block that state "signals set for 23mph".  [speed limit is 25]
Title: Re: Signals that turn red when a speeding car approaches
Post by: 1995hoo on January 01, 2014, 05:32:26 PM
Quote from: 1 on January 01, 2014, 05:19:55 PM
There was a sign (it was white on green!) in Philadelphia that said "signals set for 20 mph".


I've seen those sorts of white-on-green signs in many towns in the South, though seldom further north (note I'm not saying they don't exist further north, just that in my observation they seem more common in the South).
Title: Re: Signals that turn red when a speeding car approaches
Post by: froggie on January 02, 2014, 09:38:07 AM
QuoteA far better solution would be to simply time all the signals for the speed limit.

I fully agree, but it's not always that easy in an urban area with a dense core of traffic signals.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Brandon on January 02, 2014, 09:42:46 AM
Quote from: froggie on January 02, 2014, 09:38:07 AM
QuoteA far better solution would be to simply time all the signals for the speed limit.

I fully agree, but it's not always that easy in an urban area with a dense core of traffic signals.

It's easier than one might think.  Usually there's a street that carries the dominant traffic flow and most signals are at minor streets.
Title: Re: Signals that turn red when a speeding car approaches
Post by: froggie on January 02, 2014, 10:00:44 AM
Doesn't quite work that way in DC, where the cross streets carry significant flow themselves.
Title: Re: Signals that turn red when a speeding car approaches
Post by: Alps on January 02, 2014, 11:28:18 PM
The problem is drivers don't read. I saw the sign, I didn't speed, but 3 cars in front of me did. Good job, idiots, now we all have to wait longer. I probably set fire to their cars or something.