On average, two children die and about 50 are injured every week when someone accidentally backs over them in a vehicle, according to KidsAndCars.org, a nonprofit group that pushed the government to begin tracking such tragedies. And more than two-thirds of the time, a parent or other close relative is behind the wheel.

Now, auto safety regulators have decided to do something about it. Federal regulators plan to announce this week that automakers will be required to put rearview cameras in all passenger vehicles by 2014 to help drivers see what is behind them. The National Highway Traffic Safety Administration, which proposed the mandate in late 2010, is expected to send a final version of the rule to Congress on Wednesday.

Cars are filled with safety features that have been mandated by government regulators over the years, including air bags and the Liddy Light, the third brake light named for Elizabeth Dole, who made it standard as secretary of transportation in the 1980s.

But the rearview camera requirement is one of the biggest steps taken to protect people outside of a vehicle.