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NHTSA’s Boast of Increase in Number of Four-Star Rollover Ratings for SUVs is Misleading

June 22, 2005

NHTSA’s Boast of Increase in Number of Four-Star Rollover Ratings for SUVs is Misleading

Statement of Public Citizen President Joan Claybrook*

The National Highway Traffic Safety Administration’s announcement that more SUVs and pickup trucks are getting four-star ratings in rollover tests is misleading in a number of ways and does not necessarily mean that auto manufacturers are designing safer SUVs that are less prone to rollover. The fact is that the number of fatalities in rollover crashes – about 10,000 each year – remains in an upward trend.

NHTSA’s announcement does not explain, for example, that the better ratings are partly the result of a change in the testing regime, which added a dynamic test component and has produced grade inflation. The agency began using this test for vehicles starting with the 2004 models. The agency’s computation of the scores has a one-way ratchet – that is, to increase scores but not decrease scores for poor performance in the dynamic test.

Rather than trumpeting these scores, NHTSA should have expressed its serious concern about the highly popular 2005 Ford Explorer Sport Trac, the two-wheel-drive version of which earned a mere two stars. This vehicle is inexplicably excluded from the list appended to the press release, along with several other 2005 low-scoring vehicles.

In addition, NHTSA fails to highlight the fact that at least seven vehicles tipped up during the dynamic test, including the very dangerous Ford E-150 15-passenger van. Consumers Union has a policy that it will not recommend vehicles that tip up during NHTSA’s dynamic test. No vehicle that tips up should get a four-star rating, as did the Chevrolet Equinox. NHTSA also buried a significant difference in the test for at least one vehicle, the Chevrolet Tahoe 4×4 pickup. In testing this vehicle with electronic stability control (ESC), the vehicle did not tip up, yet it did when tested without ESC. Consumers should be informed of the difference that ESC can make to a vehicle’s rollover propensity.

No SUV earned five stars, the highest rating, even in 2005 models. Earning a higher score on these tests is also misleading, because unlike every other area of the New Car Assessment Program (NCAP) test, there is no minimum standard for rollover propensity and therefore no floor on how rollover-prone a vehicle can be. The Senate version of the highway bill pending in a House-Senate conference committee would require NHSTA to set such a minimum rollover propensity standard. The Senate bill also contains new ejection prevention and roof crush requirements, which could save many lives in rollover crashes, as rollover safety remains largely unregulated. These provisions should be enacted this summer as part of the highway bill.

There are other serious omissions in the NCAP program that were pointed out by the government accountability office in a report released in April 2005. The report recommended NHTSA adopt a rollover crashworthiness test, which would greatly contribute to consumer information about the survivability of a rollover crash.


* Joan Claybrook was administrator of NHTSA from 1977-1981.