On June 6, the Federal Motor Carrier Safety Administration (FMCSA) and National Highway Traffic Safety Administration (NHTSA)—agencies of the U.S. Department of Transportation (DOT)—proposed requirements for automatic emergency braking (AEB) systems on heavy motor vehicles (88 Fed. Reg. 43174). The proposal would require AEB systems on vehicles weighing more than 10,000 pounds (4,536 kilograms).
The rulemaking was mandated by the Bipartisan Infrastructure Law (the Infrastructure Investment and Jobs Act), and safety recommendations from the National Transportation Safety Board (NTSB) have included AEB and other crash-avoidance systems on new highway vehicles.
AEB systems use multiple sensor technologies to sense when a vehicle crash is imminent. Current forward collision warning (FCW) systems rely on cameras and radar-based sensors or a combination of camera and radar sensors. An FCW-only system alerts a driver of an impending rear-end collision with a lead vehicle so the driver can take action to avoid a crash. An AEB system automatically applies a vehicle’s brakes if the driver hasn’t done so or supplements the driver’s braking to avoid a crash. The proposal would require both FCW and AEB systems.
If a final rule is issued, the AEB system requirement would be phased in over a 3-year period. The DOT considered making the requirement retroactive for in-service vehicles but decided against it.
An estimated 42,915 people were killed in motor vehicle crashes—up from 38,824 in 2020.
“The crash problem addressed by heavy vehicle AEB is substantial, as are the safety benefits to be gained,” according to the DOT, which intends for the proposal to address lead-vehicle rear-end, loss-of-control, and rollover crashes and their resulting fatalities, injuries, and property damage.
Heavy vehicles are involved in about 60,000 rear-end crashes annually, according to data from the NHTSA’s Fatality Analysis Reporting System and Crash Report Sampling System cited in the proposal. The speed of the striking vehicle is a factor in the severity of a crash. Striking vehicles traveling at or under 30 miles per hour (mph) were responsible for approximately 1% of fatalities. Although striking vehicles traveling faster than 55 mph were responsible for approximately 17% of crashes, those crashes resulted in 89% of the fatalities from rear-end crashes.
The FMCSA proposal would ensure AEB and electronic stability control (ESC) equipment required by the NHTSA on commercial motor vehicles (CMVs) is maintained and operated safely.
The DOT stated that if all vehicles covered by the proposed rule were equipped with AEB and ESC systems, 19,118 crashes would be prevented and 155 lives saved annually. The rule also would reduce 8,814 nonfatal injuries.
Moreover, the NHTSA has conducted research into the effectiveness of AEB systems at its in-house testing facility, the Vehicle Research and Test Center. Asian and European Union countries have already adopted or are considering adopting AEB regulations for heavy vehicles, according to the DOT.
Comments on the proposal are due September 5.
Last year, the FMCSA and NHTSA proposed establishing a speed-limiter requirement for CMVs. The speed-limiter rulemaking is among the trucking industry’s top concerns, according to the American Transportation Research Institute (ATRI).