Comment Re:Traffic Lights (Score 2, Informative) 615
This is a common misconception, in the "traffic world" when computing the optimum cycle length for a signal, the sum of the yellow light and green light is considered as one, after the yellow time has been determined. The proper way to calculate the length of a yellow light is as such, a driver shall have sufficient time to either:
a) travel through the intersection safely, before the light turns red, or
b) safely come to a stop (b/c there's not enough time to make it though the intersection safely)
So, what exactly do I mean by 'safely' you ask...
The yellow light should be long enough for a driver, who is traveling at the speed limit and within close range of the intersection, to pass safely thorough the intersection without accelerating.
Unfortunately, most traffic engineers either didn't learn this in school, or some moron thought they had a better idea to make them 1 second long. When a yellow light isn't long enough for someone to process that the light is yellow, and then make a clear decision if they can pass through the intersection safely, you get a "dilemma zone." A dilemma zone is when you can't safely travel through the light or safely stop before the light turns red (i.e. safely is not slamming on your brakes).
a) travel through the intersection safely, before the light turns red, or
b) safely come to a stop (b/c there's not enough time to make it though the intersection safely)
So, what exactly do I mean by 'safely' you ask...
The yellow light should be long enough for a driver, who is traveling at the speed limit and within close range of the intersection, to pass safely thorough the intersection without accelerating.
Unfortunately, most traffic engineers either didn't learn this in school, or some moron thought they had a better idea to make them 1 second long. When a yellow light isn't long enough for someone to process that the light is yellow, and then make a clear decision if they can pass through the intersection safely, you get a "dilemma zone." A dilemma zone is when you can't safely travel through the light or safely stop before the light turns red (i.e. safely is not slamming on your brakes).
