Traffic signal systems are designed to minimize delay. An individual intersection operates most efficiently when it is allowed to respond to traffic demand in a fully actuated mode. Fully actuated operation allows the traffic signal to adjust the cycle length and phase split times on a cycle-by-cycle basis.

At all intersections, vehicles tend to group into “platoons.” Once a platoon is established, delay can be reduced by keeping the platoon moving through adjacent signals. The coordination of traffic signals (operating more than one signal in a system) can provide smooth progression along an arterial.