PASSENGER CAR EQUIVALENCIES FOR LARGE TRUCKS AT SIGNALIZED INTERSECTIONS. INTERIM REPORT

The objective of this report was to develop passenger car equivalents (PCE's) for trucks traveling straight through a level, signalized intersection based on vehicle type and position of vehicle in queue. Data were collected at three different sites and included: length of queue, classification of vehicles, and total travel time for each vehicle measured from start of green to the time the vehicle's rear axle crossed the stop line. An analytical model was developed to estimate PCE values based on total travel time and vehicle type. Using this model, PCE values were developed for 2-axle, single-unit; 3-axle, single-unit; 4-axle combination; and 5-axle combination trucks. An approximate equation was subsequently developed to predict the PCE's for large vehicles based on the number of axles. This research concluded that position of vehicle in queue significantly affects the PCE of the 5-axle trucks but does not affect the PCE value of the smaller single-unit trucks. It was further concluded that the PCE value used to calculate the heavy vehicle adjustment factors in the 1985 Highway Capacity Manual is inadequate for the large 5-axle combination trucks. Therefore, the PCE values generated from this study were condensed into two values; one for light trucks and one for heavy trucks. Furthermore, the heavy vehicle adjustment factor equation was modified to analyze the effects of light and heavy trucks separately using the recommended PCE values developed in this report.

• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011

  Texas State Department of Highways & Public Transportation

  Transportation Planning Division, P.O. Box 5051
  Austin, TX  United States  78763

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Molina Jr, C J
  • Messer, C J
  • Fambro, D B
• Publication Date: 1987-5

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 63 p.

Subject/Index Terms

• TRT Terms: Adjustment factors; Automobiles by type; Equations; Estimating; Heavy vehicles; Light trucks; Mathematical models; Passenger car equivalence; Queuing; Signalized intersections; Travel time; Trucks
• Uncontrolled Terms: Vehicle type
• Subject Areas: Highways; Motor Carriers; Operations and Traffic Management; I71: Traffic Theory;

Filing Info

• Accession Number: 00471855
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-87/397-2, TTI 2-18-85-397-2, Research Rept 397-2
• Contract Numbers: Study 2-18-85-397
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jul 31 1988 12:00AM