ARLINGTON, Va, (WUSA9) -- The number of cars and SUVs offering crash prevention systems which warns drivers they're about to hit something and auto braking systems that make cars stop by themselves has doubled since 2012.
The Insurance Institute for Highway Safety crash tested two dozen new vehicles at 12 and 25 miles per hour.
"We'll see if the auto brakes keeps us from crashing. There's the warning, and the auto brake," says one tester.
IIHS Executive Vice President and Chief Researcher David Zuby says, "The kinds of sensors that support the action of these front-crash prevention systems are the very same kinds of sensors that one day will allow cars to drive themselves."
Twenty-one of the 24 test vehicles earned "advanced" or "superior" ratings, three received "basic" scores.
Four vehicles earned perfect scores when equipped with both collision warning and automatic breaking. The BMW 5-series, the BMW X%, the Hyundai Genesis and the Mercedes Benz E-class.
In addition to luxury brands, the 2014 Buick Regal, Chevy Impala and Dodge Durango also tested well.
The IIHS says it already sees improvements from automakers since it launched its ratings on front crash prevention systems las September.
The Insurance Institute for Highway Safety says cars and SUVs will have to earn an "advanced" rating or better to win a 2015 Top Safety Pick Award which will be announced in December.