House Joint Resolution No. 23, 2002 Session of Virginia's General Assembly, requested that the Virginia Transportation Research Council and the Crash Investigation Team of Virginia Commonwealth University's Transportation Safety Training Center conduct a study of highway crashes involving trucks and other large vehicles stopped on the roadway or shoulder and struck in the rear. The purpose of the study was to determine the spatial and perceptual factors, physiological elements, and ingredients that combine to cause or materially contribute to these crashes; how and why these crashes occur; and practical countermeasures to reduce the number and severity of these crashes. To answer the question of how and why these crashes occur, Virginia crash data from 1997 through 2001 were analyzed. In only a few crashes was a large truck stopped on the roadway or shoulder struck in the rear by a passenger vehicle. Rear-end crashes in which the leading vehicle was stopped were more numerous, but single-vehicle roadway departure crashes into parked vehicles were more severe. Environmental, roadway, and surface conditions had little influence. The major contributing factor was driver inattention. With regard to the psychological and perceptual factors contributing to these crashes, it is likely that large trucks are more conspicuous than other stopped vehicles because of their size, unique profile, and requirements for reflectorized tape. However, large trucks stopped or parked continue to be struck in the rear by passenger vehicles. The cause here is also driver inattention in several forms, none of which can be directly attributed to any particular crash without a detailed crash investigation. As to possible countermeasures, two approaches stand out: increasing driver attention and removing large trucks from the shoulder. Existing methods for increasing driver attention include using infrastructure warning systems and continuous shoulder rumble strips. Future improvements to driver attention are linked to technically advanced collision warning systems that will enter the marketplace before 2012 and provide an automatic warning to drivers of possible collisions. Removing large trucks from the shoulder is more of a problem and is tied to the larger issue of the supply and demand for public and private commercial vehicle parking. Short-term improvements include amending and strictly enforcing existing parking regulations, developing a pilot program to alert truck drivers of available parking facilities, and investigating the use of Virginia's weigh stations for large truck parking. The long-term approach includes conducting studies designed to document the extent of large truck parking on the ramps and shoulders of Virginia's limited access highways, assessing the adequacy of large-truck parking statewide, and prioritizing locations with the greatest need for public and private development of large-truck parking facilities.
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