WASHINGTON — Years late, the Transportation Department issued a rule Monday that will require rearview technology in all new cars and many light trucks — an effort to reduce deaths and serious injuries caused by backup accidents.

The final rule issued by the National Highway Traffic Safety Administration will require all new vehicles under 10,000 pounds and built beginning May 1, 2018, to meet the new rear-visibility standards. The rule includes buses and trucks; motorcycles and trailers are exempt.