Shortest permitted green?

[Pete from Boston]

Is there a standard in the MUTCD or otherwise on the shortest a green phase in a three-phase light should be? They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

[roadfro]

I don't think there is an actual MUTCD-specified minimum green time.

However, FHWA's Traffic Signal Timing Manual indicates that the minimum green time from a small local street or driveway to satisfy driver expectancy is 2-10 seconds.

I'd be more upset about a 5 minute cycle length... Even some of the busiest intersections on the Las Vegas Strip max out the cycle length around 3 minutes.

[mrsman]

Does the Boston Globe (or other local newspaper) have a traffic columnist?  Maybe an equivalent out of the radio or TV?  Many cities have a weekly columnist that takes questions from the public about traffic and they will reach authorities.

I remember reading in one of these columns (I believe it was the Orange County [CA] Register) where someone complained about a short signal phase and the columnist reached out to the engineers and they discovered that one of the sensors wasn't working properly and they fixed the timing. 

[SectorZ]

Is there a standard in the MUTCD or otherwise on the shortest a green phase in a three-phase light should be? They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

What movement did they make six seconds?

[Michael]

At night, I've seen this signal have a one second green.  The yellow was longer than the green (the minimum 3 seconds mentioned in the MUTCD)!

[UCFKnights]

At night, I've seen this signal have a one second green.  The yellow was longer than the green (the minimum 3 seconds mentioned in the MUTCD)!

Orlando has a few that are really short as well, and with the photo enforcement combined with drivers who don't pay attention due to long waiting times, there's plenty of cycles where 0 cars manage to get through. Orlando is notoriously awful at timing lights. It nearly never makes sense.

[webny99]

At night, I've seen this signal have a one second green.  The yellow was longer than the green (the minimum 3 seconds mentioned in the MUTCD)!

I would think at that point, it would just not change at all. There are several signals around me where, at night, all directions are red. Then whichever direction is sensor-triggered by an oncoming car will turn green for a phase, then yellow and back to red. Then everything will stay red again until the next car comes along!

[roadman]

They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

Wellington Circle has ALWAYS had long queues on all approaches waiting to go through, even well before the casino came to town.  IMO, trying to "fix" the problems there by adjusting signal timings is akin to putting lipstick on a pig.

[Rothman]

Looking at the mess that it is, it makes me wonder if there is a feasible solution.  I doubt it.

[michravera]

Is there a standard in the MUTCD or otherwise on the shortest a green phase in a three-phase light should be? They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

To the contrary, back in 1980, there was a "smart" light at CASR-16 and Elk Grove-Florin Rd in Sacramento county that would, at times of minimal use, start to cycle every few minutes just in case some vehicle had failed to trip the sensor. Several times, I would approach the intersection along Elk Grove-Florin and see the light green, see it turn yellow and then back to green without ever going red (or green for the traffic on CASR-16). Green, Shmeen.

[Pete from Boston]

They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

Wellington Circle has ALWAYS had long queues on all approaches waiting to go through, even well before the casino came to town.  IMO, trying to "fix" the problems there by adjusting signal timings is akin to putting lipstick on a pig.

From talking to a lot of locals that use this movement regularly, the timing was drastically shortened when the circle got its recent surface makeover paid for by the casino.

[Pete from Boston]

Is there a standard in the MUTCD or otherwise on the shortest a green phase in a three-phase light should be? They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

What movement did they make six seconds?

Middlesex Ave. southbound where it meets the main part of 16.

[jeffandnicole]

Is there a standard in the MUTCD or otherwise on the shortest a green phase in a three-phase light should be? They reworked Wellington Circle, an intersection just north of Boston, to include a SIX-SECOND GREEN (could be seven, my stopwatch accuracy is ±1 second). This causes a five-minute wait for lines of about a dozen cars apiece to get through on that particular movement.

The first thing that comes to mind is the simplest possibility that people overlook because they focus on conspiracies.

Is there simply a defect in the sensor?

Sometimes, they're not that easy to pick up.  Most transportation agency people going thru a light are on the main road, or aren't familiar with how the signal should operate.  Now, I know many want to think that every person working with a transportation agency is familiar with all aspects of the transportation agency, but that's far from true.  Just like whatever job you have, you know your portion, but you don't know what other divisions of your job fully entail.  When you get paid, you get your check or direct deposit, but you don't know what the payroll clerk did to eventually get you your pay.

Even if a transportation person familiar with the light goes thru the intersection, they may be on the main route, benefiting from the green.  If they are stopped by a red light, that's normal too.  And time of day can matter.   If a light has a rush hour and non-rush hour setting, one of those can be messed up.  Someone going thru at 8:45am may not have an issue; someone going thru at 9:15am will.  I find issues with lights at night are the hardest to get resolved, because transportation people simply aren't working at night.

So, call 311.  Or if there's a specific transportation number dealing with signals that can be called, call them.  Be specific as to the times you've seen the issue, and the timing of the issue. 

As for me personally, the shortest green I've seen is on Rt. 29 at S. Warren Street, leaving the office parking lot.  During the morning rush, I referred to it as a token green which is about 2 seconds long when one vehicle is detected, and maxes out at 4 or 5 seconds for multiple vehicles.  At other points during the day, it's a relatively normal green length when needed, although a little short for the amount of traffic leaving the complex during the afternoon rush hour.

[Michael]

At night, I've seen this signal have a one second green.  The yellow was longer than the green (the minimum 3 seconds mentioned in the MUTCD)!

I would think at that point, it would just not change at all. There are several signals around me where, at night, all directions are red. Then whichever direction is sensor-triggered by an oncoming car will turn green for a phase, then yellow and back to red. Then everything will stay red again until the next car comes along!

I think the light was set to only change when it detected a car, but I've seen it change for a second without any cars there.  I didn't time it, but my best guess is that it changes every few minutes to release a car that may not have been detected.

Is there simply a defect in the sensor?

The same light I referred to above had that happen once.  On the same approach I linked to in my previous post, a few car lengths of the road before the light was being repaved.  The workers were sawing through the old pavement, and must have cut through a loop because the light would not change at all.  I was able to get the light to change by pushing the pedestrian crossing button.