Abstract: A “smart” transit signal priority and control system includes a universal interface that enables incoming signals transmitted from approaching mass transit vehicles to request priority treatment at any traffic signal. The universal interface also enables a wireless communication link between traffic signal controller equipment and approaching mass transit vehicles and supports both electrical and data interfaces to initiate transit signal priority for any type of traffic signal controller, so that any messaging protocol used by an approaching mass transit vehicle is capable of communicating with any type of controller firmware.