An arrangement for requesting preemption from a vehicle is used in a
traffic control system. The arrangement for requesting preemption
includes a protocol circuit, a signal control generation circuit, and an
optical source. The protocol circuit is adapted to provide a plurality of
communication protocols, wherein a plurality of the communication
protocols communicate encoded data. The signal control generation circuit
is adapted to generate an output signal in accordance with at least one
of the plurality of communication protocols. The optical source is
adapted to transmit light pulses from the vehicle, wherein the light
pulses are generated from the output signal and include the encoded data
for said at least one of the plurality of communication protocols.