ADVANCE CALL SYSTEM FOR VEHICULAR TRAFFIC CONTROL

• US 3,739,332 A
• Filed: 07/08/1971
• Issued: 06/12/1973
• Est. Priority Date: 07/08/1971
• Status: Expired due to Term

• Current Assignee: Renato G. Martinez
• Original Assignee: Renato G. Martinez
• Inventors: Martinez, Renato G.
• Primary Examiner(s): Cooper, William C.
• Application Number:
  US05/160,800
• Time in Patent Office: 705 Days
• Field of Search: 340/31R,31A,35,36,37
• US Class Current: 340/919
• CPC Class Codes: G08G 1/08 according to detected number or speed of vehicles

Abstract

A vehicle moving along a traffic lane towards a light controlled intersection is sensed by a first vehicle detector at a location remote from the intersection, and an '"'"''"'"''"'"''"'"'advance call'"'"''"'"''"'"''"'"' signal is generated by the first vehicle detector. The advance call signal is impressed immediately upon a traffic controller, and a capacitor or other storage means continues to hold the signal until the vehicle is sensed by a second or principal vehicle detector located close to the intersection. The traffic lights are thereby changed to green in advance of the vehicle approaching the intersection, such that the vehicle need not stop or slow down unduly. In the event that other traffic exists that might conflict with the vehicle, call signals from vehicle detectors of conflicting phases of the controller will inhibit the advance call signal causing the controller to operate in a normal mode without the advance call signal. Where a street or highway has two or more spaced apart intersections, a vehicle detector may serve in a dual capacity of providing a call signal for the controller of the first intersection and an advance call signal for the controller of the next intersection.

Claims

1. Advance call apparatus for passing signals to a traffic controller having a plurality of phases for controlling vehicular traffic in a plurality of traffic lanes approaching an intersection, said apparatus comprising:

a first vehicle detector for generating an advance call signal when a vehicle appears in a traffic lane at a location remote from the intersection;

a second vehicle detector for generating a principal call signal when the vehicle appears in a segment of the traffic lane adjacent to the intersection;

a coupling means between both vehicle detectors and said controller to call one phase of said controller; and

a signal inhibiting means coupled to receive call signals from other phases for inhibiting the advance call signal of said first vehicle deteCtor when a call signal is received representative of a vehicle appearing in a conflicting traffic lane.

2. Advance call apparatus in accordance with claim 2 further comprising a time delay means coupled to said first vehicle detector for receiving and storing the advance call signal for an interval of time subsequent to passage of the vehicle for continuing to pass the advance call signal to said controller.

3. Advance call apparatus in accordance with claim 3 wherein said storage means comprises:

a capacitor for receiving and storing a charge from the advance call signal generated by said first vehicle detector;

a leakage path coupled to said capacitor for slowly decreasing the stored signal; and

a signal level detecting means coupled to the capacitor for establishing the interval of time for continuing to pass the advance call signal to the controller.

4. Advance call apparatus in accordance with claim 1 wherein said signal inhibiting means comprises a multiple input gate for receiving call signals from conflicting phases of said controller, said gate being coupled between said first vehicle detector and said controller for passing the advance call signal to the controller only when no call signals are received from conflicting phases.

5. Advance call apparatus in accordance with claim 1 wherein a first intersection and a second intersection are spaced apart along one traffic lane, said first vehicle detector for generating the advance call signal for said controller of the second intersection being a vehicle detector for generating a call signal for a controller of said first intersection.