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Traffic control system

  • US 4,025,922 A
  • Filed: 07/07/1975
  • Issued: 05/24/1977
  • Est. Priority Date: 07/07/1975
  • Status: Expired due to Term
First Claim
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1. In a traffic control system having at least one set of traffic signal lights at a traffic intersection and traffic signal control circuit means coupled to said set of traffic signal lights, the improvement comprising:

  • (a) at least one portable interrogating unit having manually operable means for producing selectively a signal indicative of desired crossing direction, and means coupled to said manually operable means and responsive to the signal indicative of desired crossing direction for transmitting a safe-to-cross directional request signal; and

    (b) a stationary responding unit having means coupled to said traffic signal control circuit means and responsive to signals therefrom, which correspond to energization conditions of said signal lights, and to the safe-to-cross directional request signal received for producing a safe-to-cross particular directional signal upon occurrence of a signal from said signal control circuit means indicative of signal light energization conditions acceptable for safe crossing in the desired direction, and means coupled to said means for producing the safe-to-cross particular directional signal and responsive thereto for transmitting said safe-to-cross particular directional signal; and

    (c) means forming part of said interrogating unit which receive and respond to the safe-to-cross particular directional signal transmitted from said responding unit for producing a safe-to-cross signal sensible to persons who may operate said portable interrogating unit.

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