The Insurance Institute for Highway Safety (IIHS) is now rating frontal-crash prevention systems.

The IIHS says it decided to test these systems, which automatically intervene to prevent or lessen the affect of a crash, because data from the Highway Loss Data Institute (HLDI) indicates that the systems help avoid "rear-ender" crashes in the real world.

Vehicles are given ratings of Superior, Advanced, or Basic, based on two criteria.

The first is whether a vehicle has automatic braking, which can actually stop the car itself in the event of an imminent collision--as opposed to a system that can only warn a driver of an impending collision.

The second criteria is how well the system performs. To earn the top Superior rating, a vehicle with automatic braking must be able to avoid a crash or significantly reduce speeds in tests at both 12 mph and 25 mph.

Mercedes-Benz C-Class in IIHS frontal crash prevention system test.

Mercedes-Benz C-Class in IIHS frontal crash prevention system test.

For an Advanced rating, a vehicle must reduce its speed by 5 mph in one of the two tests.

Vehicles with a Basic rating do not have automatic braking, but must still be able to issue a warning to the driver within a specified time in five of seven tests under three different scenarios.

In its first round of testing, the IIHS rated 74 vehicles, all from the 2013 and 2014 model years.

Seven vehicles earned a Superior rating; six earned an Advanced rating.

The top performers were: the Cadillac ATS sedan and SRX crossover, Mercedes-Benz C-Class, Subaru Legacy and Outback, and Volvo S60 sedan and XC60 crossover.

The IIHS views front crash-prevention technology as a prelude to autonomous vehicles.

"While driver-less cars won't be on the road in any numbers anytime soon," an IIHS statement said, "the building blocks for autonomous driving promise to help prevent many crashes from happening altogether."

If automation can make driving safer it could, by the same logic, make it greener.

The main advantage of autonomous cars is their lack of unpredictability. Consistency is very important for fuel-efficient driving, so perhaps a machine programmed with a light throttle foot will be better able to achieve maximum mpg.

Visit the IIHS website for a complete list of front crash-avoidance system ratings.


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