Tough Rollover Tests for SUVs, Cars
Federal regulators are to announce today that they will conduct demanding road tests on selected 2004 passenger vehicles -- including SUVs and pickups -- to determine how likely they are to roll over in common highway emergencies.
The new tests are intended to provide consumers with the first rollover ratings based on vehicle performance, in an era when sport utility vehicles and pickup trucks have replaced the station wagon as a primary mode of transportation. As a result, there has been a sharp increase in the number of victims of rollover crashes.
To assess performance, the National Highway Traffic Safety Administration will now subject the vehicles to a test called the “fishhook” or “road edge recovery maneuver.”
The test involves jerking the wheel of a vehicle moving at 35 mph to 50 mph sharply in one direction, followed quickly by a more extreme swerve to the opposite side. That will re-create what happens when an SUV drifts off the pavement and the driver panics -- a typical sequence in rollovers, auto and government officials say. Until now, regulators have relied on a mathematical calculation based on vehicle weight and geometry.
“After all these years of SUVs on the road and rollovers, the public will finally have what we hope will be a suitable basis for informed decision-making,” said David Champion, head of vehicle testing for Consumers Union, which publishes Consumer Reports. “A dynamic test can take into account suspension, tires and the presence of stability-control systems, instead of the rather crude [calculations] they are currently using.”
The safety administration plans to demonstrate the maneuver today at a test center in Ohio. Test vehicles will be driven by a robotic controller, programmed to repeat equivalent turns of the steering wheel in different kinds of cars, pickups and SUVs. Video cameras will record whether the wheels lift up, but specially designed outriggers will keep the vehicles from flipping.
The agency initially intends to use the test to rate about three dozen model-year 2004 vehicles, with results expected to be announced early next year. An early version of the test was developed years ago by Toyota.
Government officials said it impressed them as a generally faithful model of the problems drivers face. As they sense their vehicle may go off the road, drivers typically overcorrect by steering in the opposite direction. The vehicle suddenly lurches, and the driver turns the wheel back even more sharply, risking a loss of control.
Any vehicle can flip in a crash, but SUVs and pickups are more prone to because of their high profiles and relatively narrow widths. Rollovers accounted for a quarter of all traffic fatalities in 2002, the safety administration said, and safety officials have made the issue a top priority.
Since many SUV owners do not fully realize that their vehicles are built to handle more like trucks than cars, a federal safety campaign has focused on educating drivers about the risk of rolling over. But consumer and industry groups have criticized the government’s current math-based rollover ratings as too theoretical, and they have pushed for a driving test. Congress eventually agreed and in 2000 ordered a test developed.
The agency now uses a familiar system of up to five stars for each of its vehicle safety ratings, such as rollover risk. Outwardly, that format will not change.
A stable vehicle with the most desirable rating of five stars will still have less than a 10% chance of flipping in a single-vehicle crash. One with the lowest rating -- one star -- will have odds greater than 40% of rolling.
However, the agency will calculate the ratings in a completely different manner. The agency has developed a complex statistical model that will allow it to blend the results of a vehicle’s road test performance with its weight and geometry characteristics, producing an overall rollover risk rating.
Industry officials have vowed to dissect the statistical model to probe for possible bias. “Auto makers will be assessing whether these new dynamic tests will provide more useful information to the consumer,” said Eron Shosteck, a spokesman for the Alliance of Automobile Manufacturers. “We need time to assess how much weight they continue to give to the [weight and geometry calculation] as part of the overall rating.”
Currently, most SUVs and pickups have only a three- or two-star rollover rating, while cars usually rate four or five stars. Safety administration chief Jeffrey Runge, formerly an emergency room doctor, has said he would not buy his children any vehicle with a two-star rollover rating.
It’s unclear whether the introduction of a road handling test will allow some two-star SUVs to move up in the ratings. Many high-end models are equipped with computerized stability-control systems that can sense the onset of a rollover and apply brakes or power faster and more reliably than a human driver can. Auto makers are hoping those systems will improve vehicle scores on the road test.
But government officials said early testing by the safety administration had not shown that the fishhook test produced dramatically different results from the current ratings. The agency “is not expecting a huge shift in the numbers,” according to one official familiar with the program. “The [math-based system] has been a pretty accurate barometer of rollover.”
The rating system is a consumer information program and does not impose any new design requirements on auto makers. But the safety administration is hoping its ratings will spur a competition to build more stable SUVs and pickups. Two model-year 2002 SUVs -- the Pontiac Aztek and the Acura MDX -- earned four stars under the current system, but none of 14 model-year 2003 models tested scored higher than three stars.
Some consumer advocates are urging the agency to do more. The National Transportation Safety Board has recommended that it evaluate computerized stability-control systems and, if shown effective, require them for all new vehicles.
“This consumer information system is just a minimum,” said Joan Claybrook, head of the Public Citizen advocacy group. “There needs to be a standard that requires electronic stability systems if a vehicle has a high center of gravity and is likely to roll over.”
