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.
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