A DIGITAL SIMULATION MODEL OF FREEWAY TRAFFIC--VOLUME I: MODEL DESCRIPTION; VOLUME II: PROGRAM MANUAL

VOLUME I DESCRIBES IN DETAIL THE PHILOSOPHY OF THE MODEL USED IN THE SIMULATION. INDIVIDUAL FREE-FLOW SPEEDS ARE ASSIGNED USING A NORMAL DISTRIBUTION (MAXIMUM PERMITTED RANGE IS MEAN PLUS OR MINUS 3 STANDARD DEVIATIONS). HEADWAYS ARE ASSIGNED TO VEHICLES BY BERNOULLI TRIALS USING THE ARRIVAL RATE PER SECOND. A BUFFER LENGTH IS PROVIDED SO THAT TRAFFIC CONDITIONS WILL BE COMPATIBLE WITH MODEL LOGIC. THE MODEL IS TIME-ORIENTED USING A ONE-SECOND INCREMENT. THE VEHICLES WILL PLAN AND CARRY OUT LANE CHANGES TO EXIT OR PREPARE TO EXIT, TO AVOID LARGE DECELERATIONS, TO GET FROM BEHIND A SLOW LEADER, TO MERGE, AND TO MOVE AWAY FROM LANES WITH POTENTIAL OR ACTUAL UPSTREAM CONFLICTS. OUTPUT INCLUDES FREQUENCY DISTRIBUTIONS OF TRAVERSE TIMES, DELAYS, SPOT SPEEDS, TIME HEADWAYS, AND LANE-CHANGING RISKS, AND TABULATIONS OF 'UNUSUAL' OCCURENCES SUCH AS VEHICLE STOPS, LARGE DECELERATIONS, MISSED EXITS, ETC. A TOTAL ROAD LENGTH OF 80,000 FEET WITH TWO, THREE, OR FOUR LANES AND SIX RIGHT-HAND AND SIX LEFT-HAND OFF/ON RAMPS LOCATED ARBITRARILY CAN BE SIMULATED. COMPUTER TIME TO SIMULATION TIME RATIO IS 20:1 ON AN IBM 360/509 VOLUME II IS THE PROGRAM MANUAL. IT ALSO CONTAINS AN APPENDIX WITH KNOWN PROGRAM ERRORS. /BPR/

• Corporate Authors:

  Midwest Research Institute

  425 Volker Boulevard
  Kansas City, MO  United States  64110-2299
• Authors:
  • Kobett, D R
  • Sommerville, D I
• Publication Date: 1969-3

Subject/Index Terms

• TRT Terms: Computer programs; Computers; Freeway operations; Gap acceptance; Headways; Mathematical models; Traffic simulation
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00227261
• Record Type: Publication
• Source Agency: Traffic Systems Reviews & Abstracts
• Report/Paper Numbers: 2 Vol
• Files: TRIS
• Created Date: Jul 27 1970 12:00AM