Automobile air bags designed for the American market are not necessarily appropriate for Canadian drivers, says a UBC researcher who has been studying accidents involving air bags for nearly four years.
Assoc. Prof. Douglas P. Romilly, coordinator of UBC's Road Safety Research Group, says current air bag restraint systems in vehicles sold in Canada are designed to match American driver behaviour and need to be adapted for use in Canada where a far higher percentage of drivers wear seat-belts.
His research group is currently involved in gathering and analyzing vehicle accident data and performing experimental research related to air bag effectiveness. The group's efforts are part of a nationwide effort sponsored by Transport Canada to improve vehicle safety.
"In the United States between 20 to 70 per cent of drivers might be belted, depending on the state. In Canada it's more like 93 per cent," Romilly says.
"The reason for the difference includes better driver attitude, good seat-belt legislation combined with police enforcement, and reduced court settlements for unbelted occupants involved in vehicle accidents -- all of which lead to enhanced safety on the road."
Injuries sustained when air bags deploy during low impact collisions have caught the attention of Canadian manufacturers. Unlike the United States, Canada does not currently have regulations regarding air bags. When air bag-related injuries occur, Canadian manufacturers can find themselves held liable, while in the U.S. they can point to government regulations which specify installation requirements and performance criteria.
UBC's Road Safety Research Group, which includes Romilly and three full-time investigators -- Mike Macnabb, Roy Klymchuk and Stephen Ribarits --is working in conjunction with seven similar research teams across the country and Transport Canada. The teams will determine how air bags need to be adapted for Canadian drivers and what industry requirements, if any, should be imposed.
Initial findings, following study of about 500 accidents in which air bags were deployed, indicate that the impact threshold for triggering the air bag restraint system should be raised so they do not deploy during low speed collisions, Romilly says. They also suggest the air bags should inflate with less force since the majority of Canadian drivers are already restrained by their seat-belts.
Current air bags can deploy at speeds of up to 300 kilometres per hour. The threshold speed changes required to release air bags vary substantially between vehicle type, being anywhere between 15 to 25 kilometres per hour, Romilly says.
Air bag-related injuries become noteworthy when drivers might otherwise have escaped without injury or may have been sufficiently protected by their seat-belts.
The more serious or fatal injuries can occur when a driver or passenger is "out of position" in the vehicle, Romilly says.
Air bags were initially designed to fulfil the worst case energy absorption requirements -- protecting larger adult males seated well back from the steering column and not wearing seat-belts during a high-speed frontal collision. Children and smaller adults riding in the front seats and positioned very close to the air bag are essentially "out of position" for the existing design.
Also, children in rearward-facing car seats in air bag-equipped vehicles are at risk.
"Most of the testing in low-speed conditions, where seat-belts are used, is starting to indicate that an air bag is not beneficial because of the injuries they may cause," Romilly says.
Romilly points out, however, that there is a huge discrepancy between the number of fatalities caused by air bags and the number of lives saved by them.
"Given the three or four people killed in Canada by air bags and the number of people who might have been killed if air bags weren't present, there's no comparison. So nobody can say that overall these air bag systems are not being effective.
"Can we improve them? Yes, we believe we can, and that's what all the research is about."
Among the research group's initial findings are that the combination of seat-belt and air bag can be very effective, and that safety can be further enhanced with the use of pre-tensioning seat-belts such as those used by Volvo and Mercedes. The group will recommend that air bags in Canadian vehicles be adapted to deploy in higher speed-change impacts, with less force, and be redesigned to take into consideration smaller drivers.
The group would also like to see the development of smart air bags which would only deploy if the seat position they protect is occupied. This would greatly reduce costs incurred by insurers to replace air bag systems, which cost on average about $2,500 per deployment.