Fifteen major auto manufacturers have committed to meet new standards that are important first steps toward improving occupant protection in front and side crashes involving cars and light trucks (SUVs or pickups). Together with the Institute, the Alliance of Automobile Manufacturers led the effort to develop the voluntary standards.
One set of requirements will improve head protection for people riding in passenger vehicles that are struck in the side. The other requirements will reduce the likelihood of override and underride in serious front-to-front crashes between cars and light trucks by requiring the energy-absorbing structures of the two vehicle types to overlap.
The impetus for the agreements is growing concern about the changing mix of passenger vehicles on U.S. roads. In 1980 pickups and SUVs accounted for only about 19 percent of recent model vehicles registered. A decade later they accounted for 23 percent, and now they account for about 37 percent of registered vehicles. This proliferation has fanned concerns about what happens in crashes between light trucks and cars.
Major automakers pledged last February to address some of the problems caused by incompatibility in the designs of light trucks and cars that can increase the crash risks for car occupants in collisions with SUVs or pickups (see Status Report special issue: vehicle incompatibility in crashes, April 26, 2003).
Two working groups of engineers and other technical experts from car companies and safety groups were convened in 2003. One group addressed incompatibility in front-into-side impacts, while the other concentrated on front-to-front crashes. Besides developing the first set of requirements, the working groups defined accelerated research programs to develop future requirements.
Voluntary approach is faster
The Institute "signed on to this initiative primarily because it offered a faster track to address crash compatibility problems," Institute president Brian O'Neill explains. "It takes years to produce standards through the federal regulatory process. In contrast, this voluntary process very quickly produced some interim standards, and new research has been identified that should lead to further improvements in the near future."
The automakers have agreed to design their vehicles to meet the head injury performance requirements of either the federal government's side-into-pole test or the test the Institute conducts for consumer information, using a moving deformable barrier with the front-end geometry of a typical SUV or pickup (see Status Report special issue: side impact crashworthiness, June 28, 2003).
By the 2008 model year, at least half of all new passenger vehicles will meet one of these requirements (about 25 percent of cars already do). By the 2010 model year, all new passenger vehicles will meet the head injury requirements of the Institute's moving deformable barrier test. The pole test requirements won't be an option.
Meeting these requirements will mean automakers will have to install airbags designed to protect drivers' heads. Institute research indicates that side airbags with head protection reduce the risk of death by as much as 45 percent (see "Head-protecting side airbags reduce driver fatality risk by 45 percent," Aug. 26, 2003).
Automakers also have agreed to accelerated research, beginning this year. This is expected to lead to injury criteria requirements for body regions in addition to the head. Researchers will investigate the potential benefits in front-into-side crashes of enhancing the structural designs of vehicle fronts as well as their sides.
Pickup trucks and SUVs will be designed so their principal energy-absorbing structures overlap the federally mandated zone for bumper protection on cars. If this isn't feasible, manufacturers may install secondary energy-absorbing structures such as "blocker" beams overlapping car bumper zones.
This will mean the front ends of light trucks will be more likely to engage those of cars in front-to-front crashes instead of overriding the cars. The increased engagement will enhance the ability of the front ends of both vehicles to absorb crash energy and keep damage away from the occupant compartments.
Some SUVs and pickups already meet these requirements, and all of them will do so by the 2010 model year.
"The result should be less override and underride and, therefore, reduced injury risk in serious head-on crashes," O'Neill says. "Follow-up agreements will lead to further improvements."
For ideal performance in a head-on crash, the energy-absorbing structures of the two vehicles should engage and remain engaged during the collision. Then if the front-end stiffnesses of the vehicles are matched and are less stiff than the occupant compartments, the front end of each vehicle will crush and reduce the risk of intrusion into either compartment. This will allow the vehicles' restraint systems to provide effective protection. The front-to-front follow-up research phase of the automakers' agreements eventually should lead to this kind of performance.
The research will include a series of barrier and vehicle-to-vehicle crash tests. These should lead to dynamic test requirements that go beyond simple geometric matching. The tests will lead to better matching of the front-end forces in head-on crashes between cars and light trucks. Then front-end stiffnesses can be matched to optimize performance in serious head-on crashes.
Participating automakers are BMW, DaimlerChrysler, Ford, General Motors, Honda, Hyundai, Isuzu, Kia, Mazda, Mitsubishi, Nissan, Subaru, Suzuki, Toyota, and Volkswagen. Only Porsche declined to participate.