ESTIMATES OF THE PREVALENCE AND RISK OF FATIGUE IN FATAL ACCIDENTS INVOLVING MEDIUM AND HEAVY TRUCKS

摘要

This paper presents results from a report prepared by the University of Michigan Transportation Research Institute (UMTRI) for the Federal Motor Carrier Safety Administration (FMCSA) in support of the Hours of Service rulemaking. Baseline estimates of the prevalence and risk of truck driver fatigue in fatal accidents are presented. Estimates of the vehicle miles of travel and fatal accidents involving fatigue are developed for various segments of the trucking industry. The incidence of fatigue accidents is combined with the travel data to estimate the overall risk of fatigue in fatal accidents. The study uses data from the UMTRI Trucks Involved in Fatal Accidents (TIFA) files and the 1992 Truck Inventory and Use Survey (TIUS) conducted by the Bureau of the Census. Fatigue in fatal accidents is tabulated by power unit type, trip distance, for-hire versus private carriers, time of day, and hours driving. Only the first three factors are also available in the TIUS data. Travel estimates from TIUS are used to estimate the risk of truck driver fatigue in a fatal accident per vehicle mile traveled (vmt). For the remaining factors, a relative risk of fatigue, given involvement in a fatal accident is calculated. Risk estimates per vehicle mile traveled are compared with risk estimates based only an accident data and found to be similar for the available factors.