Sometimes the least understood aspects of automobile safety concern not advanced technology systems such as air bags or anti-lock brakes but older equipment that is taken for granted.
This is true for vehicle mirrors, a basic safety device that auto pioneers figured out would allow motorists to monitor activity behind them and make safe lane changes.
Federal regulators rarely study the role of mirrors in accidents and have no estimates of how many highway deaths are caused because of lapses in rear-view vision. Government standards for mirrors have remained the same for 20 years, even as vision technology has changed and European manufacturers have raced to come up with new models.
But in response to a petition by AM General Corp., the National Highway Traffic Safety Administration is in the early stages of setting a new rule for mirrors and more advanced vision systems that might use video cameras.
AM General, which makes Hummers and Humvees sold by General Motors Corp., is seeking permission to put a convex mirror instead of a flat one on the driver's side, said Mike Kunz, AM General's government relations chief. Kunz said such a feature would give motorists a broader rear view of the road.
The current rules say light trucks and cars must have one driver-side mirror and an inside mirror, both of which must provide a certain field of view that is specified in highly technical terms. A passenger-side mirror is not required, though if provided, it can be flat or convex.
NHTSA rules do not attempt to regulate the size or location of blind spots that exist on almost all vehicles. For some large trucks, these blind spots can be particularly severe.
Consumers are dissatisfied with existing mirror systems, judging by the widespread popularity of aftermarket mirrors that motorists buy and mount in various places on their cars. The aftermarket products include oversized, convex and multiple-view mirrors.
Marko Yamaguchi, manager for Fit System mirrors, estimates that U.S. consumers purchase $250 million worth of aftermarket mirrors annually. That means millions of mirrors are being stuck on vehicles by people who want better rear vision than that provided by the original manufacturer.
"The main purpose is to help people when driving," Yamaguchi said.
Though such a simple statement seems painfully obvious, federal regulators have never acknowledged that the existing mirrors are deficient or that motorists need help.
"They certainly need to do a better job with mirrors," said Gerald Donaldson, research director for Advocates for Highway and Auto Safety, a private group based in Washington. "Existing mirrors are completely inadequate. We think mirrors ought to be required on both sides of all vehicles. Also, short drivers, including many women, have a very limited field of view. Why should we allow one group of people to have different fields of view when it directly affects safety?"
Donaldson said the safety agency generally has put lesser importance on rules and standards for equipment that helps motorists avoid crashes than on equipment that helps them survive. Thus, we have a lot of emphasis on air bags and seat belts, but less on items such as mirrors and stability systems, he said.
The petition by AM General seeks NHTSA's permission to install convex mirrors on the driver's side, but NHTSA also is examining whether to allow aspherical mirrors. Already installed on new cars in Europe, aspherical mirrors have a flat right half and a convex left half to help reduce the blind spot and provide an undistorted rear view.
A move to convex or aspherical mirrors on the driver's side probably will be controversial because they could reduce the driver's ability to judge the closing speed of vehicles and make safe lane changes, NHTSA officials say. Thus, they are in no rush to approve the request.
This year, NHTSA put out a request for comment on new rules for mirrors and video camera systems that would provide an electronic display of traffic around the sides and rear of a vehicle. If you want to send the agency comments, visit the Web site at dms.dot.gov and do a "simple search" for docket 12347.
NHTSA experts acknowledge that advanced camera systems offer the promise of eliminating blind spots, but adapting them would be difficult.
It still must be determined where the video displays would be located inside the cars and how well motorists would adjust to the new systems.
Officials at the agency say it will take years to write and implement any new standard, even though technology is racing ahead. AM General asked in March that federal regulators address its request to approve aspherical mirrors before federal regulators spend years evaluating new video technology.
But the electronic systems already are hitting the aftermarket, which the government does not regulate. Fit Systems, for example, is marketing a single-camera video system that is intended to help drivers when backing up, Yamaguchi said.
This year, the company unveiled at a trade show a three-camera system that provides full vision around the vehicle. It plans to begin selling it later this year for an estimated $2,000.
Even though advances in mirror technology can help improve motorists' rear-view vision, existing mirrors often are misused, experts say.
Ralph Vartabedian cannot answer mail personally but responds in this column to automotive questions of general interest. Please do not telephone. Write to Your Wheels, Business Section, Los Angeles Times, 202 W. 1st St., Los Angeles, CA 90012. E-mail: firstname.lastname@example.org.