COUNTY-WIDE TRAFFIC SIGNAL SYSTEM

A JOINT PROJECT WAS UNDERTAKEN BY BALTIMORE COUNTY WITH THE CITY OF BALTIMORE TO UPDATE AND INTEGRATE THEIR TRAFFIC CONTROL SYSTEM. MANY OF THE CITY CONTROLLERS WERE OF A FIXED-TIME NATURE, AND OTHERS DEPENDED ON ACTUATION INFORMATION SEVERAL MILES FROM THE INTERSECTION. THE ANALOG COMPUTERS INSTALLED BY THE CITY HAD PROVED NO LONGER ABLE TO COPE WITH CHANGING TRAFFIC CONDITIONS. SINCE FUNDS WERE NOT AVAILABLE TO REPLACE ALL THE CONTROLLERS, A SYSTEM WAS DESIGNED TO ACCOMMODATE THE RESULTING MIX, AND TO OPERATE IN BOTH A CENTRALIZED AND DECENTRALIZED MODE DEPENDING ON TRAFFIC CONDITIONS AND THE TIME OF DAY. AN IBM 1800 PROCESS CONTROLLER WAS CHOSEN TO GATHER TRAFFIC INFORMATION, DETERMINE THE ACTIONS REQUIRED FOR TRAFFIC SIGNAL CONTROL, VERIFY EXECUTION, EVALUATE THE RESULTS, AND COMPILE DAILY INFORMATION ABOUT TRAFFIC FLOW AND VOLUME AT THE INTERSECTIONS. ALL DECISION PROCESSES ARE ACCOMPLISHED BY STORED PROGRAMS. OPERATION OF THE COMPUTER SYSTEM AND SYSTEM INTERFACES WITH COUNTY AND CITY DEPARTMENTS AND ORGANIZATIONS ARE DESCRIBED. THE BASIC SYSTEM IS THE ONE DEVELOPED IN SAN JOSE, CALIF., AND FIRST OPERATED IN WICHITA FALLS, TEX.. INSTALLATION AND MAINTENANCE COSTS FOR THE SYSTEM AND FOR THE FIRST 21 MODERNIZED INTERSECTIONS ARE TABLIFIED. ONLY LIMITED STUDIES HAVE BEEN MADE TO DATE OF THE EFFECT OF THE SYSTEM ON TRAVEL TIME SAVINGS.

• Supplemental Notes:
  • Vol 35, No 6, PP 14-18, 1 FIG, 2 PHOT
• Authors:
  • Clifford, E J
• Publication Date: 1970-11

Media Info

• Serial:
  • Public Safety Systems

Subject/Index Terms

• TRT Terms: Actuated traffic signal controllers; Centralized traffic control; Computer programs; Counties; Information processing; Intersections; Magnetometers; Metropolitan areas; Traffic actuated controllers; Traffic delays; Traffic flow; Traffic signal control systems; Traffic signal controllers; Traffic volume; Vehicle detectors
• Old TRIS Terms: Centralized control
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225920
• Record Type: Publication
• Files: TRIS
• Created Date: May 3 1971 12:00AM