TESTING AND EVALUATING DETERMINISTIC MODELS OF TRAFFIC FLOW

A STUDY WAS CONDUCTED BY AIRBORNE INSTRUMENTS LABORATORY TO EVALUATE DETERMINISTIC MODELS OF TRAFFIC FLOW. THE MODELS CONSIDERED REPRESENTED SOLUTIONS OF THE GENERALIZED CAR- FOLLOWING EQUATION WRITTEN AS EXPRESSIONS RELATING AVERAGE SPEED AND AVERAGE DENSITY. ONE OF THESE SOLUTIONS WAS FOUND TO BE A BEST FIT TO TWO DISTINCT SETS OF DATA--1224 VELOCITY -DENSITY PER-LANE VALUES AVERAGED FROM ALL THREE LANES OF THE JOHN LODGE FREEWAY. THIS BEST FIT WAS DETERMINED BY USE OF A NONLINEAR REGRESSION PROCESS APPLIED DIRECTLY TO THE DATA. THE TECHNIQUE FOR SELECTING THIS BEST MODEL INCLUDED USE OF THE SUM OF RESIDUALS AS WELL AS A STATISTICAL TEST OF HYPOTHESIS BASED ON RANK-ORDERING. VALUES OF THE STANDARD PARAMETERS FREE SPEED AND MAXIMUM FLOW COMPARED CLOSELY WITH PREVIOUS ESTIMATES FOR THE SAME DATA, BUT THE EXPONENTS IN THE CAR-FOLLOWING EQUATION WERE HIGHER THAN IN ANY PREVIOUS MODEL. CONTINUOUS MULTIREGIME MODELS WERE CONSTRUCTED BY COMBINING MODELS FITTED TO THE LOW AND HIGH VEHICLE-DENSITY REGIONS. A LINEARLY WEIGHTED TRANSITION REGION, BETWEEN 45 AND 75 VPM, WAS DEFINED BY EXAMINATION OF A HIGH-ORDER POLYNOMIAL CURVE FIT. THESE MULTIREGIME MODELS WERE BETTER FITS THAN THE SINGLE-REGIME CASES, BUT WERE ANALYTICALLY MORE COMPLICATED. A MULTILANE EXPERIMENT INDICATED THAT THE BEST SINGLE-REGIME MODEL CLASS FITTED THE RIGHT-LANE DATA OF A TWO-LANE ROAD AS WELL AS IT FITTED THE TWO-LANE DATA ITSELF. ADDITIONAL LANE-BY-LANE DATA, COVERING THE FULL SENSITIVITY RANGE, IS INDICATED AS A NECESSARY REQUIREMENT TO FURTHER SUPPORT THIS CONCLUSION. /AUTHOR/

  • Supplemental Notes:
    • Adm, Cpr-11-5199
  • Corporate Authors:

    Airborne Instruments Laboratory

    Cutler-Hammer, Incorporated, Commac Road
    Deer Park, NY  USA  11729

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  USA  20590
  • Authors:
    • Abramson, P
    • Amster, G S
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00227010
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS
  • Created Date: Aug 13 2004 6:47PM