Government rolls out new auto rollover test

WASHINGTON -- After years of using a dry, mathematical formula to predict rollover risk, the government is adding a wheel-squealing road test intended to give consumers more information about a vehicle's handling capabilities.

Automakers say the road test will reward the best-handling vehicles in each class by highlighting performance measures the formula could not assess. One example is stability control, a system that applies brakes to specific tires and decelerates if it senses a driver is veering off course.

The government's auto safety agency is considering two different road tests and will announce its decision Tuesday at its test facility in Ohio. In the future, the government's five-star rating system for rollover risk will factor in both road test results and the mathematical approach.

Highway driving

In one test, a vehicle is driven in a straight line at 60 miles per hour and then abruptly turns. In the second, a vehicle is driven in a straight line at 50 miles per hour, turns left, then sharply turns right.

The mathematical formula uses the vehicle's width and center of gravity to produce a rating. One star means a vehicle has a rollover risk of more than 40 percent. A vehicle that earns five stars has a risk of less than 10 percent.

In general, sport utility vehicles and pickup trucks are more top-heavy and tend to get lower marks under the mathematical approach.

"All the old test tells you is that tall, thin things fall over before short, wide things," said Chris Tinto, director of safety regulations at Toyota Motor Co. "This will give consumers a better feel for what the differences are in vehicles."

But automakers want to see how the government incorporates the road test in its ratings system.

The Alliance of Automobile Manufacturers, a Washington trade group that represents 10 companies, says it is waiting to see how much weight the dynamic test gets in the ratings.

The government plans to continue using the mathematical formula as part of the ratings.

Better indication

R. David Pittle, senior vice president of Consumers Union, which publishes Consumer Reports, said the road test will give car buyers a better indication of a vehicle's real-world performance.

Pittle asked the agency to adopt a dynamic rollover test as early as 1996, when officials began noticing increases in SUV rollovers. But the government did not start rating rollover risk until three years ago when Congress demanded it after a massive recall of Firestone tires that were involved in rollovers of Ford Explorers.

Rollovers result in more than 10,000 deaths each year, or a little less than one-quarter of all the deaths caused by vehicle accidents. SUVs are a particular target of regulators' concern because more than 60 percent of fatalities in SUVs involve rollovers, compared with 22 percent of car deaths.

Joan Claybrook, the president of Public Citizen, says the government should mandate designs that prevent rollovers.

Automakers point out that rollovers can be the result of tires, road conditions, erratic driving and other factors. But they also say they are confident that their technology will ensure high ratings. Most have been doing their own dynamic tests for years.

"Dynamic tests are much more important," Chrysler Group chief executive Dieter Zetsche said last week. "Our real-life data is only positive, with no indication of any issue with rollover."

On the Net:

National Highway Traffic Safety Administration: http://www.nhtsa.dot.gov