Effects of Truck Size and Weights on Highways Infrastructure and Operations: A Synthesis Report.

摘要

State and federal governments place various limits on the sizes and weights of vehicles on public roads. The primary purpose is to ensure compatibility of vehicle size and weight with roadway design and operations. Of particular concern are the roadway impacts of heavy trucks, which far exceed those of passenger cars. The North American Free Trade Agreement (NAFTA) may lead to changes in truck size and weight (TS&W) regulations. NAFTA calls for unimpeded movement of trucks across the borders of the treaty partners and for the harmonization of truck standards. Although the agreement was ratified in January 1994, implementation of these provisions has been slow and the harmonization of truck standards has yet to be negotiated. Even before NAFTA, segments of U.S. industry had been pressing for increased limits on TS&W to save on freight costs. These pressures and those arising from NAFTA led the Texas Department of Transportation (TxDOT) to commission the present study from the Center for Transportation Research. The study involved a review of the literature on the effects of TS&W on highway infrastructure and safety. From this literature, we have distilled certain findings that throw light on the consequences of possible changes to TS&W regulations in Texas. As TxDOT requested, we have focused in particular on possibility of increasing the limit on gross vehicle weight (GVW). In reporting on this project, we start by describing the truck size and weight limits in place in Texas and then proceed to the lessons learned from our literature review. An annotated bibliography at the back of the report describes the studies reviewed.