How long is a yellow light??
 

What's the formula?

Varies with the speed on the street and the traffic accumulation. Determined by the initial traffic study. In our area they change based on the time of day.

My brother got a ticket for running a red light- his good friend was a CHP and timed the light, he determined the yellow was too short, wrote an affidavit and my brother got the ticket dismissed. This was circa 1988.

Depends on whether or not there is a traffic enforcement camera. When they install the camera they shorten the yellow light time. :mad:

Around northern Illinois, a yellow means "step on it" and who cares about the red.

Do not pull into the intersection until you are certain all other traffic has stopped.

Same as the width

Being a transplant from Europe I was always surprised by the US drivers attitude towards a yellow light. In Europe a yellow light means 'red light imminent, attempt to stop if it is safe to do so'. In the US a yellow light seems to mean 'last chance to beat the imminent red light'.
I'm living close to a parkway and 90% of the (frequent) accidents are caused by people jumping the red light and being hit by people who start drag racing when the light turns green. It is so insane that I've had people accelerating around me over the left turn lane when I was braking for a yellow light. With the obvious risk of sounding like an old fart I'd like to state that traffic light and stop signs are there to give everyone a chance to cross an intersection safely. Yeah, yeah, we're all experienced and good drivers, but not everyone is.

Don't you just hate it when you decide to go for the yellow light and start putting your foot into it, but the guy in front of you chickens out and brakes?