With mandatory tire monitors soon to be phased in and tougher testing standards being considered, automakers face a bumpy road to tire safety.

The legacy of the Firestone tire crisis has been increased focus on tire safety. After 271 deaths and more than 800 injuries were connected to the tread separation and other failings of Firestone tires, Congress ordered a revision of federal tire standards, which have been unchanged since 1967. Along with calling for more stringent standards, Congress also directed the National Highway Traffic Safety Administration (NHTSA) to demand that all new vehicles feature a tire-pressure monitor. While the NHTSA has already decided to start phasing in the tire monitor requirement starting late next year, it is still deliberating over the tire safety standards that it will impose on the auto industry.

The agency’s proposed new tire safety standards have instigated a debate, which has caused the NHTSA to postpone its June 1 deadline for a final decision. No new deadline has been set. Tire makers are up in arms about the agency’s proposals, calling them unnecessarily strict. According to the NHTSA, its proposed rules would cost the tire industry about $282 million annually; tire makers say the figure will be more than that. Furthermore, about a third of the 287 million passenger car and truck tires sold in the country every year might flunk the new standards, says the NHTSA. Its proposed rules, however, could prevent 27 deaths and 667 injuries every year from crashes due to blowouts and other tire failings.

While the debate on new tire standards is still raging, the NHTSA has come to a decision on mandatory tire-pressure monitors. The agency was originally planning to order automakers to implement a ‘direct’ technology system with sensors placed in each wheel to measure the tire’s pressure and temperature. But this ‘direct,’ or smart-tire technology, was criticized as being too expensive and not necessary by opponents, including some automakers. They pushed for an ‘indirect’ technology, which uses wheel speed sensors on existing antilock brakes to measure how fast each wheel is spinning. If one wheel’s rotational speed exceeds the others, then the vehicle’s computer infers that it is underinflated and warns the driver. This system does not indicate which wheel is going flat, however. It is cheaper but not as accurate as smart-tire technology, which the federal government says can save up to 70 lives and prevent more than 10,000 injuries a year. In a compromise, the NHTSA recently decided to let automakers use either system in a three-year phase-in period. Beginning in November 2003, automakers must install one of the systems in 10% of their vehicles, then 35% the year after that, and finally 65% in the third year. The period will allow the agency to evaluate the two technologies and decide on a final rule for cars and trucks made after Nov. 1, 2006.

Although this compromise is a blow to suppliers of direct-monitoring techniques, they are unfazed. Most are confident that the need for smart-tire technology will grow during the phase-in period, with OEMs using about 15 million tire-based sensors during the first year and later employing up to 60 million per year by the period’s end. In addition, automakers may not have to carry all the cost, as safety-conscious consumers are willing to pay for greater security. The question still remains, however, if consumers will spend as much as $200 per vehicle for this sophisticated monitoring technology. Many suppliers are also expecting an immediate need for their devices in large vehicles such as minivans, pickup trucks, buses and 18-wheelers because variable loading in these vehicles compromises the accuracy of indirect methods. “We feel confident that there’s a market for direct-pressure measurement as early as the 2004 model year,” says Steve Hendry, marketing manager for Motorola’s sensors division (Tempe, Arizona).

Most automakers already offer their customers both the direct and indirect systems as options. Carmakers, who were resistant to the prospect of being forced to implement one system, are relieved the ruling gives them both choices. However, the compromise has some detractors like the Rubber Manufacturers Association, a trade group. The association’s spokesman, Dan Zielinski, says that the indirect method may not warn drivers in time, lulling them with a false sense of security.

Sources: Tire Safety Technology Prepares to Hit the Road
Charles J. Murray
EE Times, May 3, 2002
http://www.eetimes.com/story/OEG20020503S0077

Automated Tire Monitors Coming in 2003
Dina ElBoghdady
Washington Post, May 31, 2002, Page E01
http://www.washingtonpost.com/wp-dyn/articles/A36839-2002May30.html

Proposed Tire Rules Raise the Bar and Concerns
Justin Hyde
Reuters, May 30, 2002
http://www.auto.com/industry/tire30x_20020530.htm