Following a full investigation, the National Transportation Safety Board (NTSB) recently determined that the probable cause of a fatal January 2008 motorcoach accident in Mexican Hat, Utah, was the driver’s diminished alertness due to inadequate sleep.

The driver, Welland Lotan, a sleep apnea patient, struggled with CPAP acceptance, including compliance to the treatment in the days before the accident, the AP reported.

The investigation conducted by the Board found that the driver’s state of fatigue affected his awareness of his vehicle’s excessive speed and lane position during a downhill mountain grade on a rural secondary road. The Board attributes part of the accident’s severity to 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.

On January 6, 2008, about 3:15 PM MST, a 56-passenger motorcoach with a driver and 52 passengers on board departed Telluride, Colo, en route to Phoenix, Ariz. The motorcoach was part of a 17-motorcoach charter with a planned route along Colorado State Route 145. However, the lead driver planned an alternate route that included US Route 163/191 through Utah due to the closure of Route 145 because of snow.

The motorcoach descended a 5.6% grade leading to a curve to the left approximately 5 hours after the trip began. 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 360-degree rollover, coming to rest on its wheels. The roof of the motorcoach separated from the body of the vehicle during the rollover, 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.

"This tragic accident was entirely preventable," says Mark Rosenker, acting chairman for the NTSB. "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."

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.

Following the results of the investigation, the NTSB made eight recommendations to federal and state government agencies, trade associations, and the motorcoach operator. Among the most significant are 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.

A synopsis of the accident investigation report, including the findings, probable cause, and safety recommendations, can be found online. The complete report will be available in several weeks.

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