How long must a yellow traffic signal be on?

Question

Is the length of time related to the posted traffic speed?

Answer 1

Mine are around 5 Seconds in Maryland.

Answer 2

Not nearly long enough

Answer 3

3 Seconds, but it doesnt always work out that way

Answer 4

3 to 5 seconds. It's a NHTSA standard.

Answer 5

The actual supposed minimum is 2.7 seconds.

Better is 4 seconds, along with a 1 second pause between yellow ending and a green turning on. But this decreases thru-put at busy intersections, causing traffic backups.

National  traffic standards.

Yes you can fight a "running red light ticket" if the yellow is too short.