I'm thinking if it was something really bad they were evacuating from (chemical attack, nuclear attack, coordinated terrorists, etc.) then stoplights and traffic control officers would be largely ignored. I, for one, would not be sitting there waiting for my left turn arrow to turn green if there was an attacking mob closing in behind me.

You'd also think that they'd deploy all that camera/traffic light stuff during NORMAL times, to deal with the daily traffic congestion. Why wait for an evacuation if the infrastructure is already in place?