ICBC has long known that whiplash is the most common type of injury in motor vehicle accidents. We also know that a well placed head restraint can have a big effect on reducing or even eliminating many whiplash injuries. As a result, pressing car makers and governments for improved head restraint design has been high on the agenda for many years. ICBC's Vehicle Safety and Research department started a head restraint rating program in 1993.
(4.5mb) - Simulation of stopped vehicle being rear-impacted at 32 km per hour (slow motion).
As a member of the International Insurance Whiplash Prevention Group (IIWPG), ICBC has rated seats and head restraints in cars sold in the Canadian market for their ability to protect occupants from whiplash in rear-impact crashes.
These ratings are based on a two step process.
First, the head restraint geometry is measured using the Head Restraint Measuring Device. To be effective, the head restraint must be high enough and close enough to support the head when the car is struck in the rear. If the geometry is marginal or poor, the car is given an overall poor rating. If the geometry is good or acceptable, the seat is then given a dynamic (crash) test.
The second (dynamic) test measures the forces on a specially designed rear-impact dummy in a simulated crash equivalent to being rear-impacted by another car travelling at 32 km/h. If the seat performs well in this test, it maintains it's good or acceptable rating. If it does not perform well in this test, it is downgraded by one or two categories.
IIWPG Members include:
In order to rate head restraint effectiveness, ICBC developed a tool for assessing head restraint geometry - the ICBC Head Restraint Measuring Device. The program was so successful that it is now being duplicated in other countries, including the U.K. The Thatcham program uses a "Head Restraint Measuring Device," purchased from ICBC, as the tool for assessing head restraint geometry - as do both the Insurance Institute for Highway Safety in the U.S. and the National Roads and Motorist Association (NRMA) in Australia. There are now 180 of these ICBC-produced devices in use around the world - primarily by auto manufacturers and their seat suppliers who use it to design head restraints that will get a good rating from the insurance research agencies mentioned above (including ICBC).
Several studies have illustrated the relationship between good head restraint design and injuries in rear-impact collisions. One study by a U.S. insurer showed that for each vehicle size category, cars with a head restraint that were rated "good" by the ICBC device have a 14 - 24% reduction in rear-impact collisions compared to cars with head restraints that were rated "poor". One auto manufacturer's study showed that improvements in head restraints resulted in a 44% reduction in whiplash injuries compared to the previous model year.
The U.S. Government's National Highway Traffic Safety Administration (NHTSA) found that head restraint geometry is so important they have required all cars sold in U.S. after September 2007 have improved head restraint geometry (as measured with the ICBC device.
When this program started in 1993 in B.C., less than 10% of new cars had "good" head restraint geometry. Most 2007 model year cars now have "good" geometry, and all new cars will meet this standard for model year 2008 (as per U.S. regulations). ICBC, and members of the IIWPG have now implemented new testing requirements which include both good geometry and meeting new requirements in a simulated crash test. This test replicates the forces experienced when a stopped car is rear-ended by another car of equal weight travelling at 32 km/h.
Manager, Vehicle Safety and Research
Insurance Corporation of B.C.
The fourteen-page technical bulletin "A Procedure for Evaluating Motor Vehicle Head Restraints" (PDF).