Traffic control systems

Claim 1

A TRAFFIC LIGHT CONTROL SYSTEM FOR ASSUMING CONTROL OVER A TRAFFIC SIGNAL SYSTEM INCLUDING A TRAFFIC LIGHT SIGNAL UNIT HAVING MEANS FOR DISPLAYING RED, GREEN AND AMBER LIGHTS FOR CONTROLLING TRAFFIC APPROACHING AN INTERSECTION FROM VARIOUS DIRECTIONS AND A SIGNAL CONTROLLER FOR EFFECTING PERIODIC AND REPETITIVE ACTUATION OF THE RED, GREEN AND AMBER SIGNALS IN TIMED RELATION, SAID TRAFFIC LIGHT CONTROL SYSTEM COMPRISING A RECEIVER OF ELECTROMAGNETIC WAVES INCLUDING A CARRIER FREQUENCY SIGNAL MODULATED SELECTIVELY BY FIRST AND SECOND SUBCARRIER FREQUENCY SIGNALS, EACH OF THE SUBCARRIER FREQUENCY SIGNALS BEING SELECTIVELY MODULATED BY VARIOUS DIFFERENT CONTROL SIGNALS, A FIRST CHANNEL MEANS CONNECTED TO SAID RECEIVER AND HAVING A BAND PASS CHARACTERISTIC SUCH AS TO PASS THE FIRST SUBCARRIER FREQUENCY SIGNAL AND ITS ASSOCIATED MODULATING CONTROL SIGNALS, A SECOND CHANNEL MEANS CONNECTED TO SAID RECEIVER AND HAVING A BAND PASS CHARACTERISTIC SUCH AS TO PASS THE SECOND SUBCARRIER FREQUENCY SIGNAL AND ITS ASSOCIATED MODULATING CONTROL SIGNALS, SAID FIRST AND SECOND CHANNEL MEANS EACH TERMINATING IN A DIFFERENT DEMODULATOR CIRCUIT MEANS FOR RECOVERING THE CONTROL SIGNAL ASSOCIATED WITH THE SUBCARRIER SIGNALS OF THEIR RESPECTIVE CHANNEL MEANS, FIRST MEANS CONNECTED TO SAID FIRST CHANNEL DEMODULATOR MEANS AND RESPONSIVE TO SAID CONTROL SIGNAL FOR DISCONNECTING THE TRAFFIC LIGHT UNIT FROM THE SIGNAL CONTROLLER AND CAUSING A FIRST PREDETERMINED ARRAY OF LIGHTS TO BE DISPLAYED BY THE TRAFFIC LIGHT SIGNAL UNIT, SECOND MEANS CONNECTED TO SAID SECOND CHANNEL DEMODULATED MEANS AND RESPONSIVE TO SAID CONTROL SIGNALS FOR DISCONNECTING THE TRAFFIC LIGHT FROM THE CONVENTIONAL CONTROLLER AND CAUSING A SECOND PREDETERMINED ARRAY OF LIGHTS TO BE DISPLAYED BY THE TRAFFIC LIGHT SIGNAL UNIT, CIRCUIT MEANS IN SAID SECOND CHANNEL RESPONSIVE TO ACTUATION OF SAID FIRST MEANS FOR RENDERING SAID SECOND CHANNEL MEANS INOPERATIVE AND CIRCUIT MEANS IN SAID FIRST CHANNEL RESPONSIVE TO ACTUATION OF SAID SECOND MEANS FOR RENDERING SAID FIRST CHANNEL MEANS INOPERATIVE.