The National Transportation Safety Board today determined that the probable cause of a fatal accident involving a 49-passenger motorcoach was the motorcoach driver's operation of the bus in a reduced state of alertness due to fatigue as a result of his chronic insomnia and poor quality sleep.
On October 13, 2003, a 1992 Neoplan USA Corporation 49 passenger motorcoach was traveling eastbound on Interstate 20 near Tallulah, Louisiana. As the motorcoach approached milepost 168, it drifted rightward from the travel lanes and onto the shoulder, where it struck the rear of a 1988 Peterbilt tractor semitrailer, which was stopped on the shoulder. Eight of the 14 passengers on board sustained fatal injuries. The motorcoach driver and six passengers received serious injuries. The Peterbilt driver was not injured.
The report states that the need for sleep varies among individuals. Losing as little as 2 hours of sleep a night can negatively affect alertness and performance, resulting in degraded judgment, decision-making, and memory; slowed reaction time; lack of concentration; fixation; and irritability. The Board found that this was a fatigue-induced accident although some facts are not typical of such a scenario.
For instance, the accident occurred in the late morning, not a time of day likely to induce sleepiness. The driver had not been on duty for an excessive length of time when the accident occurred. Also the driver's 72-hour history shows that he had the opportunity to obtain sufficient sleep during the three nights preceding the accident. Considering (a) the driver's preaccident behavior which was indicative of drowsy driving and (b) documented medical conditions and sleep problems including chronic insomnia, chronic pain, mild obstructive sleep apnea, and a history of interrupted sleep, the Board concluded that the motorcoach driver's operation of the bus in a reduced state of alertness due to fatigue as a result of his chronic insomnia and poor quality sleep was the probable cause the accident.
Contributing to the cause of the accident was the failure of Alpha Trucking, Inc., to perform vehicle maintenance and to provide safety management controls, which resulted in the accident tractor semitrailer being parked on the interstate shoulder with a smoking brake. The report states that Alpha Trucking's vehicle maintenance was consistently deficient as evident by the habitual and progressive mechanical neglect found in roadside inspections and the Board's postaccident investigation. As a result, the Board found that Alpha Trucking, Inc., misused the motor carrier vehicle self-inspection program by failing to employ the services of a qualified inspector and by misrepresenting the completion of vehicle repairs, thereby compromising the safety of the traveling public. Accordingly, the Board recommended that the Federal Motor Carrier Safety Administration conduct a study on the safety effectiveness of the self-inspection and certification process used by motor carriers to comply with annual vehicle inspection requirements and take corrective action, as necessary.
During the Tallulah crash sequence, many passenger seats did not remain secure in their original positions in the passenger compartment, even in the space outside the impacted area. Consequently, the Board determined that inadequate seat anchorage hardware used by Neoplan USA Corporation failed during the accident and resulted in more severe injuries to passengers. The Board found that no performance standards are in place for motorcoach seat anchorages and some anchorage systems may be inadequately designed to withstand crash forces. As a result of the investigation, the Safety Board recommended that the National Highway Traffic Safety Administration develop performance standards for passenger seat anchorages in motorcoaches.
Another reason the seats did not remain in their original positions during the accident was that several of the T-bolts that fastened the seats to the stainless-steel floor track had been incorrectly installed and/or maintained. Improperly secured motorcoach passenger seats are not likely to be identified during commercial vehicle inspections because no criteria or procedures are available for the inspection of motorcoach passenger seating anchorage systems. Therefore the Board recommended that FMCSA and the American Association of Motor Vehicle Administrators develop a method for inspecting motorcoach passenger seat anchorages and revise their inspection standards and procedures.
A synopsis of the accident investigation report, including the findings, probable cause and safety recommendations, can be found on the "Publications" page of the Board's web site, www.ntsb.gov.