STATEWIDE TRAFFIC MONITORING SYSTEM

THE MICHIGAN DEPARTMENT OF STATE HIGHWAYS HAS SIX MINICOMPUTERS CONTROLLING TRAFFIC-RECORDING STATIONS ON URBAN HIGHWAYS. IT IS EXPECTED THAT IN THE FUTURE THE PROCESSORS WILL ALSO DETERMINE SPEED AND CLASSIFY VEHICLES. A LONG-RANGE POSSIBILITY IS PEAK-PERIOD TRAFFIC-SIGNAL CONTROL. ALL SIX MINICOMPUTERS ARE STORED-PROGRAM PDC 808'S WHOSE SOFTWARE PACKAGE INCLUDES OPERATING AND UTILITY PROGRAMS AND ASSEMBLER MAINTENANCE PROGRAMS FOR MEMORY, PROCESSOR, AND 1/0. THE RANDOM ACCESS CORE COMES IN 4000-BYTE MODULES, OF WHICH UP TO FOUR CAN BE USED WITHOUT MODIFICATION. CYCLE TIME IS 8 MICROSEC. THE HIGHWAY DEPARTMENT IS ALSO INSTALLING A GREEWAY RAMP CONTROL SYSTEM IN DETROIT WHICH, EQUIPPED WITH APPROPRIATE DETECTORS, CAN ALSO MEASURE SPEED, HEIGHT, AND WEIGHT. THE DATA CAN BE STORED TEMPORARILY IN MEMORY, PUT OUT ON MAGNETIC OR PUNCHED TAPE, OR SENT OVER TELEPHONE CIRCUITS TO A CENTRAL COMPUTER TERMINAL. IN CURRENT OPERATION, THE URBAN PDC 808'S SCAN EACH OF 16 DETECTORS UP TO 15 TIMES PER SECOND (MULTIPLE DETECTIONS OF THE SAME VEHICLE ARE NEGATED). TOTALS FOR EVERY 15 MIN ARE STORED IN A BUFFER WHICH CAN HOLD UP TO 120 SUCH BLOCKS, I. E., A 30-HR RECORD. BEGINNING WITH THE 31ST HOUR, NEW DATA ARE WRITTEN OVER THE OLD. THIS SYSTEM PROVIDES A 6-HR DAILY OVERLAP. THE BUFFER IS POLLED ONCE A DAY IN BOTH PUNCHED-TAPE AND TELETYPE FORM. THE TAPE IS SUBMITTED TO THE CENTRAL COMPUTER FOR EDITING AND ANALYSIS.

• Supplemental Notes:
  • Vol 13, No 9, PP 16-17, 1 PHOT
• Corporate Authors:

  Data Processing Magazine

  ,    
• Authors:
  • Keesler, M
• Publication Date: 1971-12

Subject/Index Terms

• TRT Terms: Automatic control; Classification; Digital computers; Height; Information processing; Interchange ramps; Motor vehicles; Speed; Telemetry; Vehicle detectors; Weight
• Old TRIS Terms: Freeway ramps
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226175
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 20 1972 12:00AM