Last year, cars, trucks and SUVs had to get top crash test marks for front and side impacts as well as for rear-impact whiplash protection. Plus they had to have electronic stability control, a computerized system that helps the driver maintain control during abrupt maneuvers or on slippery roads.
This year, the Insurance Institute added a requirement for roof crush safety to protect occupants in the event of a rollover. To test roof strength, the Institute presses a metal bar against one side of the vehicle's roof. To earn a good rating, the roof must withstand 4 times the vehicle's weight while crushing less than five inches.