¥Engineers know that the majority of motorists act in a reasonable and responsible manner and that uniformity in expectations improves safety. Using
this thesis a researcher found that a 5.5 second yellow interval default setting
provides the best overall compliance.
¥If compliance can be maintained within engineering practices it should be.
¥If safety were truly the end game
here, the answer would be an inverse protocol of procedures for yellow interval
timing. The best system wide uniform yellow setting should be a 5.5
second default, except for prevailing speeds in excess of 50 mph where
it must be 6 seconds, with a minimum 0.5 second all red grace period,
and longer as indicated.