Two organizations standardize safety ratings: the Insurance Institute for Highway Safety (IIHS) and the National Highway Traffic Safety Administration (NHTSA). The IIHS performs crash and rollover tests that provide the basis for its vehicle ratings. To earn a Top Safety Pick, a vehicle must secure strong ratings in each of four tests and offer electronic stability control.    

Top Safety Pick is the highest safety rating awarded by the IIHS within each vehicle class. A “class” is another term for different vehicle types, including small cars, midsize cars, large family cars, small SUVs, large SUVs and trucks.    

NHTSA uses a 5-star safety rating to measure crash-worthiness and rollover safety. Vehicles are given ratings of one through five stars in individual crash tests that use dummies to indicate the kind and level of injuries that would be sustained by actual occupants.    

The final result is posted on that sticker you see on the window that displays the overall safety rating for the vehicle. Overall vehicle scores and crash ratings are then compared with those of cars that are similar in size and weight.     

Achieving a good safety rating is often aided by innovative design. For example, the 2012 Explorer, an IIHS Top Safety Pick, has inflatable rear safety belts, which feature a cold temperature inflator that takes slack out of the safety belts in milliseconds to enhance protection for passengers. The safety belt itself expands to about five times its original width like an airbag, to enhance protection for a rear-seat passenger in a crash.