US to require passenger cars to sound alarms if rear passengers don't fasten seat belts

Starting in September of 2027, all new passenger vehicles in the U.S. will have to sound a warning if rear-seat passengers don’t buckle up. The National Highway Traffic Safety Administration said Monday that it has finalized the rule. It also requires longer warnings when front seat belts aren’t fastened. Front seat changes take effect on Sept. 1, 2026. The agency estimates that the new rule will save 50 lives per year and prevent 500 injuries.