COMPUTER GRAPHICS: A NEW LOOK AT SIGNAL PROGRESSION

EFFORTS TO DEVELOP A PRACTICAL REPRESENTATION OF NETWORK SIGNAL PROGRESSION WHICH WOULD ALLOW ALL PARTS OF THE SYSTEM TO BE VIEWED AT ALL POINTS IN TIME RESULTED IN A WORKABLE TECHNIQUE WHICH USES A COMPUTER PROGRAM TO CONVERT THE GEOGRAPHICAL SYSTEM DATA, TOGETHER WITH THE NETWORK SIGNAL TIMING DATA, INTO A VISUAL DISPLAY RESEMBLING AN ANIMATED MOVIE USING STANDARD MOTION PICTURE FILM. THE COMPUTER PROGRAM WAS DEVELOPED TO PERFORM THE CALCULATIONS NECESSARY TO CREATE ANIMATED TIME-SPACE DIAGRAMS FROM DATA NORMALLY FOUND IN THE TRAFFIC ENGINEER'S SIGNAL TIMING RECORDS. NO PHYSICAL MODEL OF THE NETWORK IS REQUIRED. THE ONLY INPUTS ARE PUNCHED CARD DATA DESCRIBING THE GEOGRAPHY OF THE NETWORK AND TRAFFIC SIGNAL TIMING. A FORTRAN COMPUTER PROGRAM GENERATES, FOR EACH TIME INCREMENT OF THE CYCLE, A MAP OF THE NETWORK SHOWING THE CURRENT LOCATION OF THE PROGRESSION BANDS. THE MAP IS DISPLAYED ON A "COMPUTER OUTPUT MICROFILMER" WHICH CONSISTS OF AN OSCILLOSCOPE TERMINAL WITH A BUILT-IN CAMERA WHICH PHOTOGRAPHS THE MAP ASSOCIATED WITH EACH TIME INCREMENT. SINCE THE PATTERN OF PROGRESSION REPEATS ITSELF EACH CYCLE IT IS ONLY NECESSARY FOR THE COMPUTER TO PERFORM CALCULATIONS FOR A SINGLE CYCLE OF OPERATION. THE FILM IS CONVERTED PHOTOGRAPHICALLY INTO AN "ENDLESS LOOP" CASSETTE WHICH WILL REPEAT THE SAME CYCLE INDEFINITELY. THE RESULTS MAY THEN BE VIEWED AND STUDIED BY THE TRAFFIC ENGINEER FOR EXTENDED PERIODS OF TIME. DATA INPUT REQUIREMENTS ARE SUMMARIZED AND DETAILS ARE GIVEN OF HOW THE PROGRAM WORKS. OTHER USEFUL RESULTS OF THIS TECHNIQUE ARE REVIEWED.

• Authors:
  • Courage, K G
• Publication Date: 1973-9

Media Info

• Features: Figures; Tables;
• Pagination: p. 24-8
• Serial:
  • Traffic Engineering, Inst Traffic Engr
  • Volume: 43
  • Issue Number: 12

Subject/Index Terms

• TRT Terms: Graphics; Information processing; Methodology; Networks; Signals; Time signals; Traffic engineering
• Uncontrolled Terms: Timing
• Old TRIS Terms: Graphic methods
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226824
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 27 1974 12:00AM