DETROIT (AP) — In the not-too-distant future, automatic emergency braking will have to come standard on all new passenger vehicles in the United States, a requirement that the government says will save hundreds of lives and prevent thousands of injuries every year.

The National Highway Traffic Safety Administration unveiled the final version of the new regulation on Monday and called it the most significant safety rule in the past two decades. It’s designed to prevent many rear-end and pedestrian collisions and reduce the roughly 40,000 traffic deaths that happen each year.

“We’re living through a crisis in roadway deaths,” Transportation Secretary Pete Buttigieg said in an interview. “So we need to do something about it.”

It’s the U.S. government’s first attempt to regulate automated driving functions and is likely to help curb some of the problems that have surfaced with driver-assist and fully automated driving systems.