What Happened
What Happened
On June 11, 2023, about 6:17 a.m., a 2017 International truck-tractor in combination with a 2004 Heil Specification Package 406AL tank trailer (truck) was exiting northbound Interstate 95 (I-95) at the Cottman Avenue exit in Philadelphia, Pennsylvania. At this location, I-95 is an eight-lane divided highway with four lanes each in the northbound and southbound directions. In the area of the Cottman Avenue exit, the posted speed limit on I-95 is 55 mph with an advisory speed limit of 25 mph for the exit ramp. The truck, operated by Penn Tank Lines, was transporting about 8,500 gallons of gasoline from Wilmington, Delaware, for delivery to a convenience store in Philadelphia. As the truck traversed the exit ramp at an estimated speed of 44–54 mph, the driver lost control on the decreasing-radius, leftward curve, causing it to roll onto its right (passenger) side and strike the adjacent concrete barrier. A subsequent fire destroyed the truck and caused the collapse of the northbound overpass lanes of I-95. The truck driver was fatally injured as a result of the crash and postcrash fire.
What We Found
What We Found
We determined that the probable cause of the Philadelphia, Pennsylvania, combination vehicle rollover crash, postcrash fire, and subsequent Interstate 95 overpass collapse was the driver’s failure to slow the vehicle as he exited the interstate onto the exit ramp well above the posted advisory speed limit, due to inattention to the roadway potentially associated with fatigue. Contributing to the severity of the postcrash fire was the driver’s failure to secure the vehicle’s manhole cover during his pretrip inspection, which enabled the gasoline that was being transported to quickly enter the environment and spread throughout the crash area.
What We Recommended
The Importance of Mitigating Fatigue
For more than 15 years, the NTSB has advocated for and promoted fatigue management programs, such as the North American Fatigue Management Program, and their use by motor carriers to reduce fatigue-related crashes. Among the many strategies that a robust fatigue management program can promote, the Philadelphia, Pennsylvania, crash highlights the importance of drivers adopting sleep schedules that do not change substantially between their workdays and their days off.
The Benefits of Electronic Stability Control
The crash-involved truck was not equipped with electronic stability control (ESC). When installed on a vehicle, ESC can detect a loss of traction and apply braking force to individual wheels to assist a driver in maintaining vehicle control. The results of the NTSB’s simulations indicated that an ESC system could have helped to prevent the rollover in this crash at any of the speeds in the 44–54 mph range at which the truck was traveling. It remains critical that the US Department of Transportation identify opportunities to expedite the deployment of this technology to lighter commercial vehicles as well, where its capability of preventing a catastrophic outcome is even more assured.
