A federal investigation found that a fatal 2021 multivehicle crash in Phoenix, Arizona occurred because a tractor-trailer driver hauling a load of milk was too fatigued to be behind the wheel.
Additionally, the National Transportation Safety Board (NTSB) reports that drivers who fall under hours-of-service exemptions, such as the milk truck driver who was in the agriculture industry, are at a greater risk of fatigue.
The federal agency states that this crash “highlights the need for fatigue management and more action on collision avoidance and connected vehicle technologies.”
A program that would manage driver fatigue and collision avoidance technology would have prevented this incident, according to the NTSB.
“Generally, motor carriers must make a compelling safety case before regulators will grant them an exemption from safety rules. But, once Congress mandated and then expanded the agricultural hours-of-service exemption, the oversight of the carriers’ fatigue risk largely disappeared,” said NTSB Chair Jennifer Homendy. “Drivers operating under an hours-of-service exemption are at a greater risk of fatigue: an unacceptable — and avoidable — danger to every road user.”
Crash killed 4, injured 11
The crash occurred when the tractor-trailer failed to react to stopped traffic on the roadway in front of him.
Following the initial impact, the truck crossed the eastbound travel lanes, struck a concrete median and then separated. The truck cab and one passenger vehicle caught on fire and were quickly consumed by flames.
The crash killed four and injured 11.
Video footage showed the truck driver was facing forward before the crash and didn’t slow down as he approached the line of traffic. NTSB investigators found the driver had less than a six-hour opportunity for sleep the day of the crash and regularly worked 70 to 80 hours per week.
This was allowed because the trucking company, Arizona Milk Transport, operated under an hours-of-service exemption that gives unlimited driving hours for certain agricultural commodities within a 150 air-mile radius.
Despite having an exemption for its drivers, Arizona Milk Transport didn’t have a program in place to manage driver fatigue. Investigators found the company had poor oversight over its drivers and didn’t enforce its policies regarding the maximum hours its employees were allowed to work.
Safety impact of hours-of-service exemptions is unknown
The NTSB found that the safety impact of this sort of exemption is unknown. The prevalence of its use is also unknown, and the NTSB is now calling on the U.S. Department of Transportation (DOT) to gather more data on both subjects.
NTSB also wants the DOT to require companies operating under an hours-of-service exemption to adopt fatigue management programs. The recommendation was made to milk industry associations to encourage their members to adopt fatigue management programs as well.
Crash could’ve been prevented with collision avoidance tech
Collision avoidance technology would have prevented this incident from happening, according to the NTSB. The agency has issued recommendations to the National Highway Traffic Safety Association to develop standards for forward collision avoidance systems in commercial vehicles and mandate connected vehicle technology on all new vehicles.
Vehicle-to-everything, or V2X, technology allows vehicles and infrastructure to relay important safety information to other vehicles to avoid crashes. The NTSB currently has 14 open recommendations related to collision avoidance systems and V2X technologies and the issue is on its Most Wanted List of Transportation Safety Improvements.
The final investigation report on this incident and the NTSB recommendations will be available on the agency’s website in several weeks.