TRAFFIC CYCLE SPLIT SELECTORS

• US 3,774,147 A
• Filed: 02/10/1966
• Issued: 11/20/1973
• Est. Priority Date: 02/10/1966
• Status: Expired due to Term

• Current Assignee: Eagle Signal Controls Corp.
• Original Assignee: George Donald Hendricks
• Inventors: Hendricks, George Donald
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US04/534,603
• Time in Patent Office: 2,840 Days
• Field of Search: 340/35,36,40
• US Class Current: 340/910
• CPC Class Codes: G08G 1/07 Controlling traffic signals

Abstract

1. In a traffic cycle split control system for two intersecting highways, traffic detector means for said highways for detecting the passage of substantially all vehicular traffic thereon, main highway traffic density computer means to which all said detector means for the main highway are connected, cross highway traffic density computer means to which all said detector means for the cross highway are connected, the outputs of said computer means being proportional to traffic density on their respective highways, balance detector means for receiving and comparing the outputs of said computer means to determine the higher output, a plurality of adjustable impedances, a plurality of ratio detector means connected to said impedances, said balance detector means applying the higher output of said computer means through said impedances to said plurality of ratio detector means, said balance detector means applying the lower output of said computer means directly to said ratio detector means, said plurality of ratio detector means being responsive to said computer outputs to represent a ratio of main highway traffic to cross highway traffic, a plurality of local controllers, and a control circuit between said controllers and said ratio detector means for actuating one of a group of presettable traffic cycle splits dependent on said represented ratio.

Claims

1. In a traffic cycle split control system for two intersecting highways, traffic detector means for said highways for detecting the passage of substantially all vehicular traffic threon, main highway traffic density computer means to which all said detector means for the main highway are connected, cross highway traffic density computer means to which all said detector means for the cross highway are connected, the outputs of said computer means being proportional to traffic density on their respective highways, balance detector means for receiving and comparing the outputs of said computer means to determine the higher output, a plurality of adjustable impedances, a plurality of ratio detector means connected to said impedances, said balance detector means applying the higher output of said computer means through said impedances to said plurality of ratio detector means, said balance detector means applying the lower output of said computer means directly to said ratio detector means, said plurality of ratio detector means being responsive to said computer outputs to represent a ratio of main highway traffic to cross highway traffic, a plurality of local controllers, and a control circuit between said controllers and said ratio detector means for actuating one of a group of presettable traffic cycle splits dependent on said represented ratio.

2. In a traffic cycle split control system as in claim 1, a plurality of relays energizable by said ratio detector means, a plirality of local controllers, means within said local controllers for changing the traffic cycle split between said streets according to a plurality of splits, an interconnection between said relays and said local controllers, and means within said local controllers responsive to energization of said relays to change said splits.

3. In a split control system for a major street and a group of streets intersecting said major street, traffic detector means at at least one intersection, a main street traffic density computer means, an intersecting street traffic density computer means, balance detector means for receiving the out-puts of said computer means to dicern which direction of traffic flow exhibits the heavier traffic density, ratio detector means coupled to said balanced detector means to discern the ratio of heavier to lighter traffic density, split selector means energized by said ratio detector means, a plurality of local street intersection controllers, an electric cable connecting said local controllers with said split selector means, traffic cycle timers in said local controllers, a plurality of cycle split means in said timers for dividing the cycle time between main street and cross street, and relays in said local controllers controlled by said cycle split selector for selection of one of said cycle split means.

4. In a split control system for a grid of intersecting streets, traffic signals at a plurality of intersections, local traffic signal controllers controlling said traffic signals, a timer within each said controller for timing a cycle of signal change, split control means on said timer for controlling allocation of a plurality of percentage splits of right-of-way time between the two intersecting directions;

a master traffic controller including a split selector, a plurality of ratio detector means, balance detector means, an east-west traffic computer means, a north-south traffic computer means, traffic detector means for a plurality of streets in eacH direction, said detector means for all east-west streets connected to one computer means, said detector means for all north-south streets connected to the other computer means, each said computer means developing an output signal proportional to a characteristic of traffic in that direction, said balance detector means determining which output signal is higher, said ratio detector means determining by what ratio one output signal exceeds the other, said split selector means being controlled by said ratio detector means for in turn energizing one of said split control means at each said controller.

5. In a traffic control system, means for developing an electric potential for a first direction of traffic flow in accordance with a characteristic of traffic in said first direction, means for developing an electric potential for a second direction of traffic flow in accordance with a characteristic of traffic in said second direction, electrical potential balance detector means for determining the higher of said two potentials, ratio detector relay means, a plurality of potential dividers having outputs connected to said ratio detector relays, and switching means controlled by said detector means for applying said higher potential across said potential dividers.

6. In a traffic control system, electric potential developing means for developing an electric potential for a first direction of traffic flow in accordance with a characteristic of traffic in said first direction, means for developing an electric potential for a second direction of traffic flow in accordance with a characteristic of traffic in said second direction, electric potential balance detector means for determining the higher and lower of said potentials, a plurality of voltage dividers, a plurality of ratio detector means each connected to one of said voltage dividers, a pair of balance detector relay means connected to said balance detector means for respectively applying said higher potential across said voltage dividers and said lower potential to said ratio detector means, and a function selector relay connected to each of said ratio detector means.

7. A traffic control apparatus for controlling traffic flow in at least two directions, means for providing output signals representative of a characteristic of traffic in each of said two directions, reference ratio means, means for comparing said output signals and applying on of said signals to said reference ratio means to attenuate said one signal by said reference ratio, second means for comparing said attenuate one signal to the other signal, and traffic control means coupled to and controlled by said second comprising means for controlling traffic flow in said two directions in accordance with said comparison.

8. A traffic cycle split selector apparatus for controlling allocation of traffic cycle splits to a roadway intersection having two intersecting directions of traffic flow, means for providing output signals representative of a characteristic of traffic in each of said two directions, means for fixing a reference ratio, means for comparing said output signals and applying the greater to said reference ratio means to reduce said greater signal by said reference ratio, second means for comparing said reduced greater signal to the lesser signal, and traffic control means coupled to said second comparing means for controlling allocation of a particular traffic cycle split to said intersection.

9. A traffic cycle split selector apparatus for controlling allocation of traffic cycle splits to a roadway intersection having two intersecting directions of traffic flow, means for providing output signals representative of a characteristic of traffic in each of said two directions, means for fixing a reference ratio, means for comparing said output signals and applying the greater to said reference ratio means, second means for comparing said greater signal to the lesser signal, said reference ratio means coupled to said second comparinG means, and traffic control means coupled to said second comparing means for controlling allocation of a particular traffic cycle split to said intersection.

10. A traffic cycle split selector apparatus for controlling allocation of traffic cycle splits to a roadway intersection having two intersecting directions of traffic flow, means for providing signals representative of a characteristic of traffic in each of said two directions, balance detector means responsive to said characteristic signals to determine which characteristic signal is representative of the greater characteristic of traffic, means for fixing a reference preset ratio representing a ratio of characteristics of traffic in said two directions, ratio detector means coupled to said balance detector means and said reference ratio means for detecting whether the ratio of the greater characteristic signal to the lesser characteristic signal is greater than said reference preset ratio, and traffic control means coupled to said ratio detector means for controlling allocation of a particular traffic cycle split to said intersection.