Abstract: A vehicle speed control system is disclosed. The system is carried by a vehicle for automatically controlling the vehicle speed in response to external light signals. First and second light detecting means, e.g. photodetectors, detect first and second types of light signals, respectively. These signals are preferably light reflected from different colored hands on a pavement over which the vehicle passes. The first type of signal representing a highest permissible speed limit for the vehicle, the second type representing a lower, predetermined speed limit. A speed governing means, preferably a solenoid-controlled vacuum governor, is selectively energizable for limiting the vehicle speed. Circuitry of the system is responsive to the second light detecting means for energizing the speed governing means thereby to limit the vehicle speed to the predetermined limit.