US to require passenger vehicles to sound alarms if rear passengers don’t fasten their seat belts

DETROIT– Starting in September 2027, all new passenger cars in the U.S. will be required to sound a warning if backseat passengers do not buckle up.

The National Highway Traffic Safety Administration said Monday it has finalized the rule, which also requires better warnings when front seat belts are not fastened.

The agency estimates that the new rule, if fully implemented, will save 50 lives per year and prevent 500 injuries, according to a statement.

The new rule will apply to passenger cars, trucks, buses, excluding 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 in the outboard seats must also receive a warning if they do not fasten their seat belts. Center front seats will not receive a warning because NHTSA found it would not be cost effective. The agency said most vehicles already have warnings for the outboard passenger seats.

The rule also extends the duration of audio and visual warnings for the driver’s seat. The front seat rules will apply from September 1, 2026.

Rear passengers consistently use seat belts at a lower rate than front passengers, the agency says. In 2022, front seat belt use was just under 92%, while rear seat belt use dropped to around 82%. About half of car passengers killed in crashes two years ago were not wearing seat belts, according to NHTSA data.

The seat belt rule is the second major regulation issued by NHTSA in the past two months. In November, the agency strengthened its activities five-star car safety ratings, including driver assistance technologies and pedestrian protection.

Safety advocates want the Department of Transportation, which includes NHTSA, to finalize several more regulations before the end of the Biden administration, as President-elect Donald Trump has said he opposes new government regulations.

Cathy 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.