WASHINGTON - Unlike teachers who make tests tougher when too many students get high scores, federal safety officials don't plan to make it harder for cars and trucks to get five-star ratings in federal crash testing.
But they will make the tests more complicated.
James Hackney, director of crashworthiness standards for the National Highway Traffic Safety Administration, said the agency likely will propose by mid-year the addition of a high-speed offset crash test to the battery of tests vehicles must pass to be sold in the United States.
Offset crash tests will require automakers to ram vehicles into the corner of a barrier. Proponents believe such a collision is more typical of real-world accidents than straight-on collisions and better demonstrates the vehicle's structure.
Hackney said that if the new test is adopted for federal safety standards, NHTSA probably also will introduce it into its separate consumer information testing program, the five-star rating system known as New Car Assessment Program, or NCAP.
But Hackney said he does not expect or favor other significant changes in NCAP, even though more and more cars and trucks are getting higher ratings. He and others contend manufacturers are making design changes specifically to earn more stars for their products so that they can use the scores in marketing campaigns.
But the effect is the same: The 20-year-old program is getting automakers to improve the safety of vehicles, Hackney said. And raising the bar on what it takes for a car or truck to earn five stars 'does not seem reasonable to me,' he added.
The view contrasts with that of some academics, who say an exam is faulty if most test takers get high grades. By comparison, environmental regulators continue toughening clean air standards, even as factories reduce their emissions.
But the consumer-oriented NCAP is an information program, not a legal standard, Hackney said. There is no failing score. Vehicles get one to five stars, depending on the degree of protection provided to crash dummies in frontal and side-impact crash tests.
No vehicle tested so far in the 1999 model year has received fewer than three stars in any category.
Three years ago, a NHTSA research paper found that rising NCAP scores between 1979 and 1995 represented a 30 percent drop in the probabilities of life-threatening head and chest injuries in tested cars.
'It's very difficult to get five stars,' Hackney said. 'I see no reason to change those levels.'
The industry already is familiar with offset crash testing.
Offset tests are used in Europe and Australia by safety agencies and in the United States by the Insurance Institute for Highway Safety, the research arm of the auto insurance industry. Institute Vice President Julie Rochman said that if the government adopts offset crash testing, her organization will stop conducting the tests and devote its resources to other safety issues.
George Parker, vice president of the Association of International Automobile Manufacturers, welcomed the new test. 'Our members have generally supported an offset test,' he said. 'It is more representative of the real world than the full-frontal test.'
In NCAP, cars and trucks are run head-on into a barrier at 35 mph and are struck from the side by a 3,015-pound object moving at 38.5 mph. Both speeds are 5 mph higher than those required for compliance with safety standards.
An offset crash runs part of a vehicle's front into the corner of barrier. It imitates what happens when a car or truck drifts over the centerline into the path of oncoming traffic.
The full-frontal test mostly shows how well a vehicle's restraint system works. An offset crash tests a vehicle's whole structure.
David Champion, director of the automotive test division of Consumers Union, said he thinks that if NHTSA wanted to, it could 'recalibrate' its crash tests to differentiate better between vehicles.
It also could add other injury measurements in the crashes. NCAP tests measure the force hitting a dummy's head and chest. NHTSA also could measure the potential for neck, leg and foot injuries, Champion noted.
Champion, whose organization publishes Consumer Reports magazine and refers to the government crash tests in its auto reviews, agreed that more vehicles getting higher NCAP ratings is a positive development.
But, he said, he also worries that designing a vehicle for a good NCAP score may not be the best way to improve occupant safety.
'Designers are improving cars because they have seen five stars give them a lot of bragging power,' he said.
Ford Motor Co. especially has been aggressively advertising the five-star ratings of some of its vehicles.