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  United States  11729

  Bureau of Public Roads /US

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

Subject/Index Terms

• TRT Terms: Car following; Evaluation; Expressways; Mathematical models; Multilane highways; Statistical analysis; Traffic density; Traffic simulation; Traffic speed
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management;

Filing Info

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