HITCH YOUR CONTROLLER TO MY COMPUTER. - ADAPTING L.A.'S CONTROLLERS FOR COMPUTERIZED TRAFFIC CONTROL

TRW HAS RECENTLY COMPLETED THE INITIAL INSTALLATION OF ITS SAFER I COMPUTERIZED TRAFFIC CONTROL SYSTEM WHICH WAS DESIGNED TO MONITOR AND CONTROL THE FLOW OF TRAFFIC AT 112 INTERSECTIONS IN THE SOUTH BAY AREA OF LOS ANGELES COUNTY. THE SYSTEM CONSISTS OF INTERSECTION EQUIPMENT LOCATED IN THE CONTROL AREA, LEASED COMMUNICATIONS LINES, AND A COMPUTER FACILITY LOCATED AT THE LOS ANGELES COUNTY ROAD DEPARTMENT. THE INTERSECTION EQUIPMENT MONITORS THE FLOW OF TRAFFIC AND CONTROLLER STATUS, DECODES COMMAND INFORMATION RECEIVED FROM THE COMPUTER, AND GENERATES THE REQUIRED COMMANDS TO THE INTERSECTION CONTROLLER TO ADVANCE TO THE PROPER PHASE OR TO TERMINATE AN EXISTING PHASE. THE LOS ANGELES SYSTEM PRESENTED A UNIQUE SITUATION RELATIVE TO TYING THE EXISTING CONTROLLERS INTO THE COMPUTER. WITHIN THE 112 INTERSECTIONS THERE WERE CONTROLLERS FROM FIVE DIFFERENT MANUFACTURERS, COVERING NINETEEN MODELS, WITH MANY MODELS HAVING INTERNAL VARIATIONS AND CONFIGURATIONS. SOME CONTROLLERS WERE INTERCONNECTED, OTHERS WERE NOT. SOME OPERATED FROM A MASTER, OTHERS OPERATED IN ISOLATION. SOME WERE INSTALLED IN RECENT YEARS, OTHERS HAD BEEN IN PLACE FOR MANY YEARS. THE NET RESULT WAS A UNIQUE CONFIGURATION AT ALMOST EVERY ONE OF THE 112 INTERSECTIONS. TWO BASIC TYPES OF CONTROLLER ADAPTER UNITS (CAU) WERE DESIGNED WHICH WERE FLEXIBLE ENOUGH TO INTERFACE TO THIS VARIETY OF CONTROLLERS. SAFETY WAS THE PRIME CONSIDERATION AND EXISTING CONTROLLER FUNCTIONS WERE UTILIZED WHEREVER POSSIBLE. IN ADDITION TO COMMANDING THE CONTROLLERS, THE CAU'S MONITOR THE CONTROLLER'S STATUS AND TRANSMIT THAT STATUS TO THE COMPUTER. THE CAU MONITORS UP TO EIGHT DIFFERENT GREEN SIGNALS AT EACH INTERSECTION. IT ALSO MONITORS PEDESTRIAN PUSHBUTTONS, PREEMPTION DEVICES AND YELLOW SIGNALS WHERE REQUIRED.

• Corporate Authors:

  International Municipal Signal Association

  P.O. Box 187
  San Juan Capistrano, CA  United States  92675
• Publication Date: 1973-8

Media Info

• Features: Figures; Photos;
• Pagination: p. 9-15
• Serial:
  • IMSA Signal Magazine
  • Volume: 9 N
  • Issue Number: n4
  • Publisher: International Municipal Signal Association

Subject/Index Terms

• TRT Terms: Information processing; Monitoring; Traffic control; Traffic flow; Traffic safety; Traffic signal controllers
• Old TRIS Terms: Adapters; Traffic control systems
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226772
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 16 1974 12:00AM