In 1999, the most recent year for which data are available, more than 6 million crashes occurred on U.S. highways, killing over 41,000 people and injuring nearly 3.4 million others. Rear-end collisions accounted for almost one-third of these crashes1 (1.848 million) and 11.8 percent of multivehicle fatal crashes (1,923). Commercial vehicles were involved in 40 percent of these fatal rear-end collisions (770), even though commercial vehicles only comprised 3 percent of vehicles and 7 percent of miles traveled on the Nation's highways. Between 1992 and 1998, the percentage of rear-end collisions involving all vehicles increased by 19 percent. In 1999, 114 fatal crashes in work zones involved rear-end collisions, about 30 percent of the multivehicle fatal work zone crashes. Of these, 71 collisions (62 percent) involved commercial vehicles.
In the past 2 years, the National Transportation Safety Board investigated nine rear-end collisions in which 20 people died and 181 were injured (three accidents involved buses and one accident involved 24 vehicles). Common to all nine accidents was the rear following vehicle driver's degraded perception of traffic conditions ahead. During its investigation of the rear-end collisions, the Safety Board examined the striking vehicles and did not find mechanical defects that would have contributed to the accidents. In each collision, the driver of the striking vehicle tested negative for alcohol or drugs. Some of these collisions occurred because atmospheric conditions, such as sun glare or fog and smoke, interfered with the driver's ability to detect slower moving or stopped traffic ahead. In other accidents, the driver did not notice that traffic had come to a halt due to congestion at work zones or to other accidents. Still others involved drivers who were distracted or fatigued.
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