EVALUATION OF GRAVITY MODEL TRIP DISTRIBUTION PROCEDURES

A RESEARCH PROJECT WAS CONDUCTED TO EVALUATE GRAVITY MODEL TRAFFIC ESTIMATING PROCEDURE. THE PROJECT USED THE WASHINGTON, D.C. METROPOLITAN AREA AS A STUDY AREA. THE GENERAL FORMULATION IS PRESENTED FOR THE GRAVITY MODEL. THE STUDY STRATIFIES THE TOTAL TRAVEL DEMANDS OF THE AREA INTO THE FOLLOWING SIX TRIP PURPOSE CATEGORIES: (1) HOME-BASED WORK, (2) HOME-BASED SHOPPING, (3) HOME-BASED SOCIAL- RECREATION, (4) HOME-BASED SCHOOL, (5) HOME-BASED MISCELLANEOUS, AND 76) NON-HOME-BASED. THE DEFINITION OF THESE PURPOSE CATEGORIES IS THE SAME AS THOSE USED BY THE ORIGIN-DESTINATION SURVEY. AN ESTIMATE OF TERMINAL TIME WAS MADE FOR EACH ZONE BASED ON THE TYPE AND INTENSITY OF LAND DEVELOPMENT. AFTER THE INFORMATION ON ZONAL TRIP PRODUCTION AND ATTRACTION AND ZONAL SEPARATION WAS PREPARED, THE MODEL WAS CALIBRATED TO REFLECT THE OVER-ALL CHARACTERISTICS OF THE WASHINGTON METROPOLITAN REGION THROUGH A STEP-BY-STEP PROCESS: (1) DETERMINING FRICTION FACTORS, (2) BALANCING ZONAL TRIP ATTRACTIONS, AND (3) ADJUSTING FOR SYSTEMATIC GEOGRAPHICAL VARIATIONS. THE RESULTS OBTAINED BY THE GRAVITY MODEL CALIBRATED AS DESCRIBED ARE SHOWN IN A FIGURE IN THE FORM OF COMPARISON OF SCREENLINE CROSSINGS. BASED ON THE RESULTS OF THIS EXAMINATION, IT IS CONCLUDED THAT THE BASIC GRAVITY MODEL FORMULATION CAN SERVE AS A FRAMEWORK FOR FORECASTING URBAN TRAFFIC. ONE OF THE MAJOR FINDINGS OF THE STUDY WAS THE MEASUREMENT OF THE INFLUENCE THAT FACTORS OTHER THAN THOSE OF TRIP GENERATION AND TRAVEL TIME HAVE ON TRAVEL PATTERNS IN THE WASHINGTON AREA, AND THE NEED TO ANALYZE, UNDERSTAND, AND INCORPORATE THE IMPACT OF THESE FACTORS WHEN ESTIMATING URBAN TRAVEL DEMANDS.

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  • Authors:
    • Hansen, Walter G
  • Conference:
  • Publication Date: 1962

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: pp 67-76
  • Monograph Title: Trip characteristics and traffic assignment
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00227899
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Aug 15 2004 2:36AM