Why aren some traffic signals put in flashing operation late at night?
In one word: “safety”. This has been the subject of much research within NCDOT. Studies have shown that collisions may increase at locations where traffic signals operate in late night flash. With today’s modern traffic control signal equipment, wait times at sparsely traveled roadways late at night should be minimal. The NCDOT has criteria to evaluate if a traffic signal may safely operate in late night flash. If the traffic signal meets this criteria, it is monitored on a regular basis to make sure crashes do not increase during the late night flash.
