ARLINGTON, Va. — In recent frontal offset crash tests of new or redesigned small and midsize cars, every vehicle received the top rating of good and earned a "best pick" designation. The tested cars include three small models (2002 Suzuki Aerio, 2003 Toyota Corolla, and 2002 Mini Cooper) and two midsize cars (2003 Honda Accord, an inexpensive model, and the moderately priced 2002 Audi A4).
The Institute's ratings (see attachment) reflect performance in a 40 mph frontal offset crash test into a deformable barrier. Based on the results of this test, the Institute evaluates the crashworthiness of passenger vehicles, assigning each vehicle a rating of good, acceptable, marginal, or poor. The better performers among the vehicles with good ratings also are designated "best picks."
"This set of crash test results continues to demonstrate the effectiveness of consumer safety information in improving frontal crashworthiness," Institute president Brian O'Neill says. "When we completed our first set of offset tests of 14 midsize cars in 1995, only 3 earned good ratings. So far this year, all small and midsize car designs we've tested are rated good. In fact, it's now unusual for us to test a new passenger vehicle design of any type or size and not get a good rating."
The Institute previously evaluated the crashworthiness of predecessor Corolla and Accord models. In each case the performance of the new model improved, compared with the older design. The predecessor Corolla was acceptable, while the new design is rated good. The Institute has tested two predecessor Accord designs, both of which were acceptable. "Now the new Accord design is the Institute's highest-rated midsize inexpensive car," O'Neill says.
Structural design is key to good performance
All five cars the Institute tested earned good ratings for structural performance in the offset test. The occupant compartments of these cars held up well, preserving the space around the driver dummy.
A vehicle's structural design is key to its crashworthiness performance because the Institute's frontal offset crash test into a deformable barrier is especially demanding of this aspect of vehicle design. The driver side hits the barrier, so a relatively small area of the vehicle's front-end structure must manage the crash energy. This means intrusion into the occupant compartment is much more likely to occur than in a full-width test.
"If a vehicle's front-end structure absorbs and manages the crash energy so the occupant compartment remains largely intact, with little or no intrusion into the driver's space, then the dummy's movement during the crash is likely to be well controlled, and injury measures are likely to be low. In contrast, poor structural design means greater likelihood of poor control of the dummy and high injury measures," O'Neill explains.
Institute and government crash tests complement each other
The Institute's crashworthiness evaluations are based on results of 40 mph frontal offset crash tests. Each vehicle's overall evaluation is based on three aspects of performance — measurements of occupant compartment intrusion, injury measures from a Hybrid III dummy positioned in the driver seat, and analysis of slow-motion film to assess how well the restraints controlled dummy movement during the impact.
The federal government has been testing new passenger vehicles in 35 mph full-front crash tests since 1978. This New Car Assessment Program has been a major contributor to crashworthiness improvements — in particular, improved restraint systems in new passenger vehicles. The Institute's offset tests, conducted since 1995, involve 40 percent of a vehicle's front end hitting a deformable barrier at 40 mph. This test complements the federal test involving the full width of the front end hitting a rigid barrier. Both tests are contributing to improvements in crashworthiness — in particular improved crumple zones and safety cages.
The same 40 mph offset crash test is used to evaluate new cars by the European Union in cooperation with motor clubs, by an Australian consortium of state governments and motor clubs, and by a government-affiliated organization in Japan.