CHANGES IN SCHEDULE TIGHTNESS AMONG LONG-DISTANCE TRACTOR-TRAILER DRIVERS IN THE UNITED STATES

In 1994, in that year's Canadian Transportation Research Forum Conference Proceedings, results of a 1991 study that investigated the frequency of schedule-induced hours-of-service rules (HSR) and/or speed limit violations by long distance drivers of tractor-trailers were reported upon. Findings of that study indicated that approximately 25% of the drivers were likely to be in violation due to their schedules. This paper discusses the results of a 2001 study using the same approach as the earlier work. The focus here is on a subset of long distance drivers identified in the 1991 research as being at particular risk; namely, those with refrigerated trailers.