Effect of Light-Duty Trucks on the Capacity of Signalized Intersections

This paper analyzes the impacts of different light-duty trucks (LDTs) on the capacity of signalized intersections. Data were collected at two intersections in Austin, Tex., and regression analysis generated estimates of mean headways associated with various categories of LDTs, as well as passenger cars. Using the estimated headways, passenger-car equivalents were calculated, and these suggest that the impacts of LDTs should be given special consideration when analyzing the capacity of signalized intersections. For example, a single large sport-utility vehicle in through traffic is equivalent to 1.41 passenger cars, and a van is equivalent to 1.34. Such headways reduce intersection capacity and increase urban congestion.