Motor Carrier Scheduling Practices and Their Influence on Driver Fatigue

摘要

The primary objective of this report is to develop a better understanding of how the scheduling practices of motor carrier firms affect driver fatigue. The basis of this empirical research is a commercial driver fatigue model that includes driving environment (i.e., regularity of time, trip control, and quality of rest), economic pressures exerted on drivers (from customers, carriers, and the drivers themselves) and company safety practices as key factors in explaining driver fatigue. The model utilizes two measures of fatigue: frequency of close calls due to fatigue and driver perceptions of fatigue as a problem. Crash involvement is used to evaluate general safety performance. Three separate studies were conducted. First, the influence of driving environments alone on fatigue among over-the-road truck drivers was tested through a survey of 502 drivers at five geographically dispersed truck stops. A typology of driving environments was developed and the percent of drivers in each category was determined. It was found that a large number of drivers are in the 'high fatigue risk' categories. Regression analysis identified starting the work week tired and longer than expected loading and unloading time as significantly related to both measures of fatigue. Regularity of time, regularity of route, and hours of uninterrupted sleep were each statistically significant factors for one fatigue measure.