Buying a Safer Car 2004
Valuable Information on: Crash Tests, Rollover Ratings and Safety Features

Rollover Resistance Ratings
Rollover resistance ratings measure the chances that your vehicle will rollover if you are involved in a single vehicle crash. Vehicles with a higher number of stars are less likely to rollover if involved in a single-vehicle crash. A single-vehicle crash is one that does not involve another vehicle. It is important to note that these ratings do not directly predict the likelihood of that single-vehicle crash occuring.

Driver behavior, speeding, distraction and inattentiveness play a significant role in rollover crashes. Almost all vehicles involved in a rollover somehow lost control, ran off the road and struck an object such as a ditch, curb, guardrail or soft soil, causing the wheels to “trip” on the object and the vehicle to rollover. This suggests one of the best ways to avoid a rollover is by staying on the road. Electronic Stability Control (ESC) is a promising new technology to help drivers stay on the road in emergency situations.

Beginning with the 2004 model year, the rollover resistance rating is based on: 1) an at-rest laboratory measurement known as the Static Stability Factor (SSF) that determines how “top heavy” a vehicle is and 2) the results of a dynamic maneuvering test. In short, the rollover rating brings together a measure of how “top-heavy” a vehicle is with how well it performs in a severe turning maneuver on a test track. The lowest rated vehicles (1-star) are at least four times more likely to roll over than the highest rated vehicles (5-stars).

For model years 2003 and earlier, rollover resistance ratings are based on the SSF rating only. Consumers making cross year comparisons of vehicles’ rollover star ratings will need to be aware of this difference starting with model year 2004 and later vehicles.

NHTSA’s rollover resistance ratings of vehicles reflect the real-world rollover experience of vehicles involved in over 86,000 single vehicle crashes. Like side-impact crash test ratings, it is possible to compare vehicles from different weight classes when looking at rollover ratings.

It is also important to note that rollover crashes have a higher fatality rate than other kinds of crashes. More than 10,000 people die each year in rollover crashes. Remember: Even the highest rated vehicle can rollover. By wearing your safety belt you can reduce your chance of being killed in a rollover by about 75 percent.