Re:As a traffic engineer... (Score 2, Informative)

As I stated originally, with higher speeds, the All-Red time should decrease since it speed and All-Red time is an inverse relationship. The Institute of Transportation Engineers (ITE) calculations for All-Red are based upon clearing a vehicle through an intersection during the All-Red phase. In my experience most, if not all, jurisdictions allow vehicles to be in an intersection at the start of red. Philip Tarnoff of the University of Maryland Center for Advanced Transportation Technology did a study based on the delay calculations found in the Traffic Engineering Handbook and found that "neither yellow nor all-red times have a significant impace on capacity, and that all-red time will only have a significant impact on delay under heavy traffic conditions." He did his study based on traffic signals with 2-, 4-, 6-, and 8-phase cycles, and the delay increases significantly as you increase the number of phsaes. I work mostly with 2-, 3-, or 4-phase cycles, so the added safety benefit of having a longer all-red phase usually outweighs the slight increase in delay.