Control system for a traffic signal whereby an authorised vehicle sends its location to the signal control to change the operating mode of the traffic signal

摘要

A system for automatic control of a traffic signal including a transmitter on a vehicle operable to send a radio communication and a traffic signal controller associated with a traffic signal and operable to change a state of the traffic signal is disclosed. The traffic signal controller has a first independently operating mode and a second controlled mode. The traffic signal controller has a receiver to receive a communication from the vehicle and a processor to switch the mode of the traffic signal controller between it's first and second modes to let the vehicle pass through area controlled by the traffic signal. The data sent includes the current location of the vehicle, eg using a global positioning system (GPS). The processor uses the location information to determine when the vehicle is approaching a zone controlled by the associated traffic signal and accordingly to issue a trigger signal to switch the mode of the traffic signal controller. The system may monitor the vehicle to detect when the vehicle passes out the zone controlled by the traffic signal. The traffic signals may also be controlled by a central traffic control station.