DEVELOPING A PROCEDURE FOR COMPARING ALTERNATE URBAN HIGHWAY IMPROVEMENTS

THE RESEARCH EFFORT DESCRIBED WAS DESIGNED TO DEVELOP A PROCEDURE FOR COMPARING URBAN MOBILITY PATTERNS RESULTING FROM ALTERNATIVE STREET IMPROVEMENTS AND/OR TRAFFIC REGULATION MEASURES, AND FOR ASSISTING IN THE OPTIMIZATION OF TRAFFIC FLOW. THE TOOL FOR ATTAINING THE ABOVE OBJECTIVES WAS THE DYNAMIC HIGHWAY TRANSPORTATION MODEL (DHTM) DEVELOPED BY STANFORD RESEARCH INSTITUTE. THE PURPOSE OF THIS STUDY WAS TO VALIDATE THE MODEL IN AN ACTUAL NETWORK OF 100 INTERSECTIONS IN THE CITY OF SAN FRANCISCO AND WHILE DOING SO MODIFY AND MORE FULLY DEVELOP THE MODEL IN LIGHT OF ITS REAL-WORLD PERFORMANCE. THE VALIDATION WAS DIVIDED INTO TWO STAGES. THE FIRST INVOLVED TESTING THE MODEL'S ABILITY TO REPRODUCE TRAFFIC CHARACTERISTICS IN AN UNPERTURBED NETWORK; IN OTHER WORDS THE DESCRIPTIVE ABILITY OF THE MODEL. THE SECOND STAGE CONSISTED IN EVALUATING THE PREDICTIVE CAPABILITY OF THE MODEL; THAT IS, THE ABILITY OF THE MODEL TO PREDICT THE CHANGES IN TRAFFIC FLOW WHICH WOULD OCCUR WITH CHANGES IN THE NETWORK. IN THE FIRST STAGE THE MODEL WAS CALIBRATED AGAINST THE PATTERNS OF FLOW IN THE STUDY NETWORK IN 1967. THEN IN JULY 1968, CHANGES IN TRAFFIC CONTROL WERE MADE IN THE NETWORK AND FURTHER FIELD WORK CARRIED OUT TO PROVIDE A NEW BASE FOR MEASURING THE PREDICTIVE CAPABILITY OF THE MODEL IN THE SECOND STAGE. THE DESCRIPTIVE VALIDATION RUNS INDICATE THAT THE DHTM MODEL REPRODUCES FLOWS IN THE SAN FRANCISCO TEST NETWORK FAIRLY WELL. RESULTS ON HEAVY-TRAVELED HIGH-CAPACITY THOROUGHFARE WERE BETTER THAN IN LIGHTLY TRAVELED STREETS. HOWEVER, CHANGES MADE IN THE NETWORK WERE NOT REFLECTED IN THE OBSERVED TRAFFIC PATTERNS. CONSEQUENTLY, IT WAS NOT POSSIBLE TO ASSESS THE EFFECTIVENESS OF THE MODEL AS A PREDICITIVE TOOL. /BPR/

  • Supplemental Notes:
    • Adm, Fh-11-6365, 3225-031
  • Corporate Authors:

    Smith, Wilbur & Associates

    ,    

    Connecticut State Highway Department

    ,    

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Publication Date: 1969-7

Subject/Index Terms

Filing Info

  • Accession Number: 00239033
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Oct 7 1994 12:00AM