On September 20, 2004, about 4:29 p.m. central daylight time, a 1999 Freightliner truck tractor, in combination with a 1997 Trailmobile dry van semitrailer, traveling northbound on U.S. Highway 75 (US 75), in the city of Sherman, Grayson County, Texas, crossed the median and collided with a 2000 Ford Expedition sport utility vehicle (SUV) and a 1990 Ford F150 pickup truck traveling southbound on the same road. A postaccident fire ensued. The Freightliner was driven by a 45-year-old man en route from Dallas, Texas, to Kansas City, Missouri. The weather was cloudy, and the roadway was dry.
Tire marks from the accident scene, consistent with scuff marks, indicate that as the Freightliner tractor-semitrailer approached the Farm-to-Market 1417 overpass bridge at a speed of 65–70 mph, it veered leftward from the right lane, crossed the left lane, and entered the earthen median at an angle of approximately 20°. The tractor-semitrailer continued across the median and entered the southbound lanes, where it collided with the SUV and the pickup truck. The Freightliner and the SUV came to rest partially in the grass, just west of the southbound travel lanes; the ensuing fire engulfed both vehicles. The pickup truck came to rest in the southbound travel lanes.
The driver and all four passengers in the SUV and the driver and four passengers in the pickup truck were killed. Two passengers in the pickup truck sustained serious injuries. The Freightliner driver received minor injuries.
We determined that the probable cause of the September 20, 2004, median crossover accident near Sherman, Texas, was the Freightliner driver’s startle response consisting of a sudden and sharp over control maneuver to the left in an unnecessary reaction to vehicles that were traveling a safe distance ahead of the truck, caused either by the driver’s significant lack of sleep, which resulted in a brief period of sleep or attention loss while driving, or by the driver’s attempted or imminent use of a wireless device, which distracted him from his driving duties. Contributing to the severity of the accident was the use of a pickup truck cargo area bed to transport passengers despite its lack of any occupant restraint system.
