WASHINGTON, D.C. - The National Transportation Safety Board today determined that the probable cause of the motorcoach accident in Mexican Hat, Utah, on January 6, 2008, was the driver's diminished alertness due to inadequate sleep resulting from a combination of factors. The Board found that 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. Contributing to the accident's severity was the lack of an adequate motorcoach occupant protection system, primarily due to the National Highway Traffic Safety Administration's delay in developing and promulgating standards to enhance the protection of motorcoach passengers.
"This tragic accident was entirely preventable," said Acting Chairman Mark Rosenker. "More importantly, it shines a spotlight on the need for all motor vehicle operators to take responsibility for their physical fitness before they get behind the wheel."
On January 6, 2008, about 3:15 p.m. MST, 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 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.
Approximately five hours after the trip began, the motorcoach descended a 5.6-percent grade leading to a curve to the left. After entering the curve, the vehicle departed the right side of the roadway at a shallow angle, striking the guardrail, and traveled off the roadway. The motorcoach overturned in a complete 360ø rollover sequence and came to rest on its wheels. During the rollover, the roof of the motorcoach separated from the body of the vehicle, and 51 of the 53 occupants were ejected. Nine passengers were fatally injured and 43 passengers and the driver received injuries ranging from minor to serious.
Major safety issues identified by this accident investigation include driver fatigue, excessive vehicle speed, hours-of-service violations, motor carrier trip planning, motorcoach occupant protection, and emergency medical notification and response with regard to large motorcoaches traveling on rural roads.
As a result of this accident, the NTSB made eight recommendations to federal and state government agencies, trade associations and the motorcoach operator. Among the most significant are the recommendations to the Federal Highway Administration, the American Association of State Highway and Transportation Officials, and the National Association of State Emergency Medical Services Officials to work together to develop and implement criteria based on traffic patterns, passenger volume, and bus types that can be used to assess the risks of rural travel by large buses.
The NTSB also reiterated one recommendation and reclassified four recommendations to modal agencies of the U.S. Department of Transportation that incorporate two items on the NTSB's Most Wanted List of Transportation Safety Improvements:
- Enhance Protection for Motorcoach Passengers (National Highway Transportation Safety Administration)
- Require On-board Electronic Recorders (Federal Motor Carrier Safety Administration)