Multiple National-Certified Traffic Signal Tech here, so I'll lay out the rules as I know them on Signal Operation. Standard IANAL, YMMV, etc applies.flintknapper wrote:Caveat: I am NOT a lawyer…but here are my thoughts.
Sounds like you entered the intersection when the light was what I like to refer to as “stale yellow”.
You might be able to challenge your ticket based on the timing of the yellow light at the intersection. The National Standard is (1 second for every 10 mph of speed limit). Of course, other factors can be considered as well. If you go back and “time” the light (with an accurate stop watch) and find that it is below the N/S recommendations …then you MIGHT have an argument.
Also, I am not an engineer, Just a tech :) I can implement plans given to my By engineers, but I cannot and do not make them up myself ;)
While this is a 'recommended practice' (speed limit/10) it is not the law. the MUTCD (Manual For uniform traffic control devices - the standard for signals. There's a Federal, and then each state can have their own. Texas does.) requires minimum 3 seconds of yellow. That is it. Whether it is a 15mph trailer park road, or a 55mph state highway.
Could this get challenged in court as 'unsafe' in some locations? Possibly, but it is not specificaly 'against the law'.
There is a device in the cabinet known as a 'conflict monitor' that basically acts as a watchdog on the intersection. if the controller does anything 'against the rules', it instantly throws it in flashing red operation until someone can come look at it to see what it has done wrong. This device will throw the intersection into flash if there is less then 2.75s +/- about .15s seconds of yellow. It is known as a 'yellow clearance failure'. The reason they made it ~2.75s instead of exactly 3s is that about .15s variance depending on manufacturer, age, etc. (despite what most people think, electronics are not 100% perfect in timekeeping, especially when in harsh environments) They are supposed to be tested every year, as recommended by the manufacturers, to verify that they do in fact meet the standards. (This may be admissible in court if the monitor hasn't been tested ((Someone may shoot me for this, but MANY of them probably are not tested as recommended. (However, All the ones I maintain are.) There will/must be a paper trail on this.)))
So is there a chance it ran for < 3 seconds without going into flash? Yes. Will you be able to accurately measure it with a stopwatch, or even a 30fps video camera? (30fps is roughly one frame every 33ms, or .033 seconds) Possibly, but I wouldn't count on it.
Is it an engineering defect if the car does not clear the intersection in time? Possibly, however, the engineers cannot predict every situation, and many times, construction is done without any engineering changes on the signal timing.If you find that the yellow light timing for this intersection does meet the N/S, then I wouldn’t hold out much hope for avoiding the ticket. You will need to document (video) your findings and have a reliable witness testify to the same… if you choose to contest the ticket in this fashion.
The general rules regarding yellow lights are:
(A) Drivers who can safely stop before reaching the intersection should do so when they see the light turn
yellow. They have to consider their speed and their distance from the intersection when deciding whether
or not they can safely stop. If they try to decelerate too quickly then their tires might skid dangerously or
they might get “rear ended” by a car behind them.
(B) Drivers who are too close to the intersection to safely stop should continue on at constant speed. The
yellow light should give them enough time to make it completely through the intersection before it turns
red. If the light turns from yellow to red too quickly then the car will still be in the intersection when the
light turns red and a cop might give them a ticket that’s not really their fault. It would be the fault of the
city’s traffic engineers for not setting the timing of the yellow light properly.
Good luck Sir,
Flint.
Engineers are expensive, lots of municipalities do not have their own, so they have to hire a contractor, and doing so for every small construction project around an intersection would delay the construction, while the contract is placed out for bid, as well as cost extra money. As long as they can certify the intersection as 'safe' during the construction, via road closures, non-contradictory indications, not modifying the actual intersection phasing (making a T into a 4-way, etc) etc, they can do construction on or around an intersection without changing it's timing.
Does an engineer normally have to look at any/all construction plans? Yes. Is it a traffic engineer? No. Generally it is a Civil Engineer.
Do I recommend a Traffic Engineer at least LOOK at an intersection before, and occasionally during construction? Absolutely. Is it required? Not Always.
So, IANAL, I do not know the laws about running yellow lights, but that is how the signal side of it relates :)