Highway Accident Report
Motorcoach Run-Off-the-Road and Rollover
U.S. Route 163, Mexican Hat, Utah
January 6, 2008
NTSB/HAR-09/01

CONCLUSION
The National Transportation Safety Board determines that the probable cause of this accident was the driver’s diminished alertness due to inadequate sleep resulting from a combination of head congestion, problems acclimating to high altitude, and his sporadic use of his continuous positive airway pressure sleeping device during the accident trip. The driver’s state of fatigue affected his awareness of his vehicle’s excessive speed and lane position on a downhill mountain grade of a rural secondary road.

FACTS
On January 6, 2008, about 3:15 p.m. mountain standard time, a 2007 Motor Coach Industries 56‑passenger motorcoach with a driver and 52 passengers on board departed Telluride, Colorado, en route to Phoenix, Arizona, as part of a 17-motorcoach charter. The motorcoach passengers were returning from a 3-day ski trip. The normal route from Telluride to Phoenix along Colorado State Route 145 was closed due to snow, and the lead driver planned an alternate route that included U.S. Route 163/191 through Utah.

About 8:02 p.m., the motorcoach was traveling southbound, descending a 5.6‑percent grade leading to a curve to the left, 1,800 feet north of milepost 29 on U.S. Route 163. After entering the curve, the motorcoach departed the right side of the roadway at a shallow angle, striking the guardrail with the right-rear wheel and lower coach body about 61 feet before the end of the guardrail. The motorcoach traveled approximately 350 feet along the foreslope (portion of roadside sloping away from the roadway), with the right tires off the roadway. The back tires lost traction as the foreslope transitioned into the drainage ditch. The weather was cloudy, and the roadway was dry at the time of the accident.

The motorcoach rotated in a counterclockwise direction as it descended an embankment. The motorcoach overturned, struck several rocks in a drainage ditch bed at the bottom of the embankment, and came to rest on its wheels. During the 360° rollover sequence, the roof of the motorcoach separated from the body, and 51 of the 53 occupants were ejected. As a result this accident, 9 passengers were fatally injured, and 43 passengers and the driver received injuries ranging from minor to serious.