Starting in September 2027, all new passenger vehicles in the US will be required to warn if a rear-seat passenger is not buckling in their seat.
The National Highway Traffic Safety Administration said Monday it has finalized the rule, which also requires increased warnings for not wearing a front seat belt.
According to a statement, the agency estimates the new rule will save 50 lives per year and prevent 500 injuries when fully implemented.
The new rule will apply to passenger cars, trucks and buses except school buses and multi-purpose vehicles weighing up to 10,000 pounds.
Before the rule, seat belt warnings were only required for the driver’s seat.
Under the new rule, passengers sitting in the front seat of the plane must also receive a warning if they are not wearing a belt.
Front-center seats will not receive any warnings because NHTSA found it would not be cost effective.
The agency said most vehicles already have warnings for outboard passenger seats.
The rule also increases the duration of audio and visual warnings for the driver’s seat. The front-seat rules are effective September 1 of 2026.
The agency says rear passengers consistently use seat belts at lower rates than front passengers.
In 2022, front belt usage was just under 92%, while rear usage dropped to nearly 82%.
According to NHTSA data, nearly half of the automobile passengers who died in crashes two years ago were not wearing belts.
The seat belt rule is the second significant regulation from NHTSA in the last two months.
In November the agency expanded its five-star auto safety rating to include driver assistance technologies and pedestrian protection.
Safety advocates want the Transportation Department, which includes NHTSA, to eliminate several more regulations before the end of the Biden administration because President-elect Donald Trump has said he is against new government regulations.
Kathy Chase, president of Advocates for Highway and Auto Safety, urged the department to approve automatic emergency braking for heavy trucks and technology to prevent impaired driving.
