Tire pressure sensors

The National Highway Traffic Safety Administration (NHTSA) (part of the Department of Transportation) is going to mandate the installation of tire pressure sensors in vehicles starting in model year 2006. If the tire pressure falls below the recommeded level by 25% or more, the car will alert the driver to the fact. The rulemaking is motivated by the fact that underinflated tires are the cause of several accidents: it is estimated that the rule will save 120 lives and prevent 8400 injuries annually.

According to NHTSA, under-inflated tires can adversely affect fuel economy, lead to skidding and loss of control and hydroplaning on wet surfaces. It can also increase stopping distance and the likelihood of tire failures.

It will cost the auto industry on the order of $50-$70 per vehicle and save consumers about $30 due to better fuel efficiency, fewer crashes and longer tire life. According to the NYT, "The government estimates that it will cost the industry between $800 million and $1.1 billion to phase in the technology on all new vehicles from this year through 2007."

Apparently, it all started with an act of Congress in 2000 (prompted by the Firestone recalls) requiring the NHTSA to set guidelines for tire pressure monitoring systems. The agency dragged its feet for a couple of years (apparently due to the lobbying efforts of the auto industry) until safety groups sued multiple times to get the process moving and received court orders directing the NHTSA to act quickly.

For more background see the NTHSA announcement and the rulemaking. Interesting story because it illustrates the dynamics of rule-making (conflicting interests of safety groups, Congress and the auto industry), the time-scales for the passage of rules in this industry (~4 years), the process for mainstreamization of new technology (tire-monitoring systems are already in place in 2-4 MM luxury vehicles today and the adoption of this technology will be accelerated by this ruling) and because it illustrates the reactive nature of such efforts (it took a well-publicized system failure to spur decisive action).