HOW CAN WE PREVENT ROLLOVERS AND REDUCE INJURY SEVERITY IN SINGLE-VEHICLE LARGE TRUCK CRASHES?

Society pays high costs for truck crashes in terms of operational disruptions, injuries and loss of life. Among the 700 large truck fatalities that occur every year, about 400 occur in single-vehicle truck crashes and many involve rollovers. This study attempts to understand how truck driver behaviors, vehicle-factors and crash events influence large-truck rollovers and occupant injuries in single-vehicle crashes. A relatively clean crash and inventory database, named HSIS (Highway Safety Information System) is used for crash analysis. The data comes from police-reported crashes in North Carolina between 1996 and 1998. Over this three-year period, truck rollovers occurred in almost 30% of the 5,163 single-vehicle truck crashes. Rollover propensity is investigated using binary probit models; and injury severity (measured on the KABCO scale - fatal, severe, moderate, minor and none) is examined using ordered probit models. New insights emerge about the direct and indirect effects of high-risk factors. The implications are that through a combination of countermeasure strategies, we must attempt to: 1) reduce dangerous truck-driver behaviors (in particular speeding, reckless driving, alcohol and drugs, non-use of restraints and traffic control violations), 2) reduce truck exposure to roadways that have dangerous geometry, particularly more curves, and 3) explicitly deal with transportation of hazardous materials and post-crash fires.