FACTORS AFFECTING TRAVEL SPEEDS ON URBAN ROADS

A SPEED FLOW RELATIONSHIP HAS BEEN ESTABLISHED FROM THE STUDY OF NINE LENGTHS OF 4-LANE ROADS IN MELBOURNE. MORE THAN 88 PERCENT OF THE VARIABILITY IN MEASURED PEAK PERIOD TRAVEL SPEEDS HAS BEEN EXPLAINED IN TERMS OF THE SIGNIFICANT TRAFFIC AND PHYSICAL FACTORS. AT THE SAME TIME, A STUDY PROCEDURE HAS BEEN ESTABLISHED, WITH WHICH IT SHOULD BE POSSIBLE TO EXTEND THE FINDINGS TO ALL URBAN ROADS IN AUSTRALIA. IT WAS FOUND THAT SPEEDS WERE MOST EFFECTIVELY MEASURED BY A SAMPLE NUMBER PLATE SURVEY TECHNIQUE. TRAVEL TIMES, CALCULATED FROM THE MATCHING OF NUMBER PLATE RECORDED AT EACH END OF A SURVEY ROUTE WERE PROPORTIONED BETWEEN SURVEY SECTIONS ON THE BASIS OF MOVING OBSERVER RECORDS. IN THE PILOT STUDY, THE ORGANIZATION ENSURED EXECUTIVE DECISION BY THE STUDY DIRECTOR ON THE BASIS OF ADVICE FROM AN EXPERIENCED TRAFFIC ENGINEER AND STATISTICIAN. AT MILE-STONES IN THE STUDY'S PROGRESS THERE WAS FORMAL REVIEW OF WORK, BOTH COMPLETED AND PROGRAMMED. A KEY TO THE PILOT STUDY'S SUCCESS WAS THE USE OF PARALLEL REGRESSION TECHNIQUES WHICH ALLOWED THE SEPARATE ANALYSIS OF THE TRAFFIC AND PHYSICAL FACTOR DATA WITHOUT ANY LOSS OF STATISTICAL RELIABILITY. THIS FACILITY WAS DOUBLY IMPORTANT BECAUSE THE HIGH CROSS-CORRELATIONS BETWEEN REGRESSION VARIABLES MADE THE TESTING OF THE SENSITIVITY OF SPEED TO THE VARIOUS FACTORS MORE DIFFICULT. IT IS EXPECTED THAT ADDITIONAL FACTORS WHICH WOULD NEED TO BE CONSIDERED IN DEFINING A COMPREHENSIVE SPEED-FLOW RELATIONSHIP INCLUDE: ROAD CROSS SECTION TYPE, SPEED RESTRICTIONS, HORIZONTAL AND VERTICAL ALIGNMENT, NATIONAL VARIABILITY, TIME OF DAY AND WEEK, AND WEATHER. IT SHOULD NEW BE POSSIBLE TO PROCEED CONFIDENTLY IN EXTENDING THE PILOT STUDY TO COVER THE FULL RANGE OF OPERATING CONDITIONS ENCOUNTERED ON URBAN ROADS THROUGHOUT AUSTRALIA.

• Supplemental Notes:
  • 4 APP
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Publication Date: 1973-10

Media Info

• Features: Figures; Tables;
• Pagination: 41 p.

Subject/Index Terms

• TRT Terms: Data collection; License plates; Pilot studies; Regression analysis; Speed; Statistical analysis; Surveys; Traffic flow; Travel time; Urban highways
• Old TRIS Terms: Pilot study
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00226853
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 22 1974 12:00AM