Background In 1995, the agency amended FMVSS 201 (Occupant Protection in Interior Impact) to set new requirements, or upgrade existing requirements on the energy-absorbing capabilities of the A and B pillars, roof rails, and other vehicle interior components associated with serious head injuries in crashes. The regulation has been phased in for new cars and light trucks over a five-year period, starting with 10 percent of model year 1999 production and concluding with 100 percent of model year 2003 production. As of 2003, most vehicles have received upgraded padding or other energy-absorbing materials. However, an increasing proportion of vehicles are being equipped with special air bags designed to protect occupants from head impacts with roof rails or pillars and to reduce the risk of occupant ejection through side window areas: these will be evaluated separately (see "Side air bags + head air bags," 2004 starts - vehicle safety).

Objectives Estimate the effect of the new padding and energy-absorbing materials on the risk of fatal and serious head injuries. Estimate the consumer cost of vehicle modifications in response to (or in anticipation of) the new standard.

Proposed Approach The cost of FMVSS 201 modifications (without head-impact air bags) will be estimated from "teardown" analyses. Head injury rates in pre-standard cars and in post-standard cars with energy-absorbing padding will be compared in NASS data and in the enhanced FARS file that includes cause-of-death information. Overall fatality rates will also be compared in FARS data.

Status "Teardown" analyses of head-impact areas in FMVSS 201 vehicles without head air bags, and in comparable pre-standard vehicles, are underway. A contract has been awarded to perform head-impact tests, similar to the FMVSS 201 compliance test, on pre-standard vehicles. The evaluation is likely to require at least four years for sufficient crash data to accumulate.