FMVSS No. 127
The U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) has announced a new Federal Motor Vehicle Safety Standard (FMVSS No. 127) to make automatic emergency braking (AEB), including pedestrian AEB, compulsory on all cars and light trucks by September 2029.
The press release in late April 2024, titled NHTSA Finalizes Key Safety Rule to Reduce Crashes and Save Lives, stated that the standardization of AEB will save at least 360 lives and prevent 24,000 injuries per year by effectively curbing car crashes and pedestrian collisions.
“The new vehicle safety standards we finalized today will save hundreds of lives and prevent tens of thousands of injuries every year,” said Pete Buttigieg, Secretary of U.S. Transportation. “The Bipartisan Infrastructure Law is not only making historic investments in transportation, it’s also ushering in a new era of safer travel by ensuring new cars and light trucks are equipped with automatic emergency braking, making our roads safer for drivers and pedestrians alike.”
AEB Mechanics & Shortcomings
Automatic emergency braking is an ADAS feature that deploys proximity sensors to detect a vehicle or pedestrian within a range pre-set by the automaker. It automatically applies the brakes if the driver hasn’t ahead of an imminent collision.
While studies have shown the potential of AEB to prevent crashes and injuries, others are more cautionary. For example, a 2022 study from the Insurance Institute for Highway Safety found that pedestrian AEB systems were ineffective at night or on poorly lit roads. A similar study by AAA determined that current AEB systems struggled at higher speeds and experienced a high fail rate during intersection testing.
Meanwhile, AAA’s related study published in February 2024 on reverse automatic emergency braking found that current systems also need improvement, especially if a child is present behind the vehicle.
New AEB Standards
Under NHTSA standard FMVSS No. 127, pedestrian AEB technology must detect pedestrians in both daylight and darker conditions. New AEB technology must be able to stop and prevent a collision with the vehicle in front at speeds up to 62 mph. Furthermore, under this law, the AEB system should automatically apply brakes up to 90 mph if a collision with a lead vehicle is imminent and up to 45 mph in the case of a pedestrian. It applies from September 2029 to all new U.S. vehicles having a gross vehicle weight rating (GVWR) under 10,000 lbs. or 4,500 kg.
Based on previous studies on the effectiveness of AEB, this latest NHTSA standard has the potential to further reduce crashes and prevent injuries.
“Automatic emergency braking is proven to save lives and reduce serious injuries from frontal crashes, and this technology is now mature enough to require it in all new cars and light trucks. In fact, this technology is now so advanced that we’re requiring these systems to be even more effective at higher speeds and to detect pedestrians,” said Sophie Shulman, Deputy Administrator of NHTSA. “Most new vehicles already come with AEB, and we expect that many cars and light trucks will be able to meet this standard ahead of the deadline, meaning even more lives will be saved thanks to this technology.”
