WASHINGTON — The National Transportation Safety Board determined Tuesday the probable cause of a fatal 2016 collision between a motorcoach and tractor-trailer truck near Palm Springs, California, was the California Department of Transportation’s inadequate transportation management plan for stopping highway traffic near utility work, coupled with fatigue related to undiagnosed obstructive sleep apnea (OSA) and inaction by a driver because of fatigue.
In the early-morning darkness of October 23, 2016, on Interstate 10, the motorcoach was traveling at highway speed when it crashed into a stopped truck, resulting in the death of the motorcoach driver and 12 of its passengers. The truck and other traffic had been stopped on the highway by police for utility work. When traffic resumed, the truck did not move. The motorcoach struck the rear of the truck two minutes later, ramming some 13 feet into the truck’s trailer and pushing it 71 feet forward.
The NTSB determined the probable cause of the crash was Caltrans’ inadequate transportation management plan for stopping traffic, which resulted in a hazardous situation in which law enforcement did not detect the truck’s lack of movement following the traffic break and did not provide any advance warning to the bus driver of the potential for stopped traffic ahead.
The board also determined the truck driver did not resume driving after the traffic stoppage because he most likely fell asleep because of fatigue related to his undiagnosed, moderate-to-severe OSA.
Despite the fact the truck driver was severely obese and at a very high risk for obstructive sleep apnea, he had not been tested for the condition, the NTSB report said, adding that although the Federal Motor Carrier Safety Administration’s Medical Review Board MRB has developed guidance for screening for obstructive sleep apnea, the FMCSA has not disseminated this guidance to the medical examiners it certifies to perform commercial driver’s license medical examinations.
However, by law, the FMCSA can only address this issue through rulemaking, and in August withdrew a joint Advance Notice of Proposed Rulemaking for obstructive sleep apnea by FMCSA and the Federal Railroad Administration, saying current safety programs and FRA’s rulemaking addressing fatigue risk are the appropriate avenues to address OSA.
That leaves certified medical examiners to make the decision on whether a driver should be sent for OSA testing based on judgment of accepted risk factors.
However, despite the fact that while there may not be any official published "guidance" from FMCSA, the agency's website contains information relating to known symptoms of OSA, and carriers' doctors and many other doctors who do the screenings for CDL renewal have erred on the side of caution by using the MRB's recommendations and/or established medical proceedures for determining OSA for patients.
The NTSB’s investigation on the accident also revealed the bus driver had untreated diabetes, but the FMCSA-certified medical examiner did not diagnose the bus driver’s condition or refer the driver for further testing despite a positive glucose urine test during the driver’s medical certificate examination. The NTSB also found that the bus driver did not take actions to avoid the crash because he too was likely fatigued and did not expect to encounter stopped traffic.
“In this crash, not one but two commercial vehicle drivers — people who drive for a living — were unable to respond appropriately to cues that other motorists acted on,’’ said NTSB Chairman Robert L. Sumwalt. “Federal and state regulators, commercial motor carriers and professional drivers can do better. Given the stakes, they must do better.’’
The board issued eight safety recommendations based upon the findings of the investigation, making two recommendations to the FMCSA, three to the Federal Highway Administration, one to the trucking company, one to three national trucking associations and one to the International Association of Chiefs of Police and the National Sheriffs’ Association.
The abstract of the NTSB’s final report, which includes the findings, probable cause and safety recommendations is available online at https://go.usa.gov/xn22F.
The final report will be publicly released in the next several days.