Large Truck Accident Causation Final Report

To help assess proposals for further changes in federal truck weight limits, Congress requested this study through Section 158 of the Surface Transportation and Uniform Relocation Assistance Act of 1987. To conduct the study, the National Research Council convened a special Transportation Research Board committee with experts in pavements, bridges, highway safety, freight transportation economics, motor vehicle design, highway administration, motor carrier operations, and enforcement of motor vehicle regulations. The study focused on four issues identified in the study request that involve potential changes to federal weight limits for Interstate highways: (1) Elimination of existing grandfather provisions; (2) Alternative methods for determining gross vehicle weight and axle loadings; (3) Adequacy of the current federal bridge formula; and (4) Treatment of specialized hauling vehicles--garbage trucks, dump trucks, and other trucks with short wheel bases that have difficulty complying with the current federal bridge formula. For each of these issues, the study committee estimated the nationwide effects of changes in federal limits proposed by the trucking industry, highway agencies, and other groups. Projections of heavy-truck miles by type of truck, region of the country, highway functional class, and operating weight were developed for a base case and alternative truck weight regulatory scenarios. These projections were then used to estimate impacts on truck costs, pavements, bridges, and safety.

TRB's Commercial Truck and Bus Safety Synthesis Program (CTBSSP) Synthesis 4: Individual Differences and the "High-Risk" Commercial Driver explores individual differences among commercial drivers, particularly as these differences relate to the "high-risk" commercial driver. The synthesis identifies factors relating to commercial vehicle crash risk and assesses ways that the high-risk driver can be targeted by various safety programs and practices, at both fleet- and industry-wide levels.

TRB's Commercial Truck and Bus Safety Synthesis Program (CTBSSP) Synthesis 1: Effective Commercial Truck and Bus Safety Management Techniques focuses on the problems commercial truck and bus fleet managers confront, and the methods that are available to address problems in the areas of driver and vehicle safety, and more.

The objective of this report is to identify known relationships between commercial vehicle safety and crash causation factors and to prepare a synthesis of safety implications of oversize/overweight (OS/OW) commercial vehicles. This information can be used to support commercial vehicle enforcement and permitting practices and justify expenditures and investments on size and weight enforcement to enhance safety. In producing this report, insight was gained into the impacts of truck size and weight (TSW) regulations through three case studies. The state of practice in estimating large truck crash rates is complicated because of the many configurations and the wide range of possible weights for any particular configuration. This report highlights four primary findings regarding the contributions of OS/OW to commercial vehicle crashes found by its researchers.