Sorry to keep this going! As a traffic engineerl in the great state of Florida, where red light enforcement cameras are NOT legal, and someone who has timed many yellow and red clearance intervals, I thought some of you might be interested in the following link to a suprisingly interesting informational report published by ITE (Institute of Transportation Engineers) on red light running.
Most of the issues and I think some jurisdictions mentioned on this thread are disscussed in this paper mainly designed to inform people who are mandating and designing red light enforcement cameras.
I have never imagined recomending traffic stuff to anyone but the passions in this debate here are high, just as they are in the transportation engineering field itself.
by the way: I feel that private contractors should have NO - ZERO - NADA input or say on what the clearance timing is.