WASHINGTON (AP) — Transportation officials and automakers say they've agreed to make automatic braking standard in nearly all cars within six years — by 2022.

Mark Rosekind — who heads the National Highway Traffic Safety Administration — says the voluntary agreement with 20 car manufacturers means that the important safety technology will be available more quickly than if the government had gone through the lengthy process of issuing mandatory rules.

Automatic braking systems use cameras, radar and other sensors to see objects that are in the way, and slow or stop a vehicle if the driver doesn't react. It's the most important safety technology currently available that's not already required in cars.

Safety advocates have filed a petition asking the government to issue mandatory regulations. Those advocates say voluntary agreements aren't enforceable.