Automatic speed limit signal control for road, has modulated Hertz wave emitter to transmit speed limit information to vehicles

摘要

The automatic speed limit signal control for a road is installed in the speed limit display panel. It has a modulated Hertz wave emitter to transmit speed limit information to the vehicles. The emitter can be frequency modulated depending on the value of the signal code for the displayed speed. The transmission can use laser or infra-red emissions.