For several years the little sensors that supposedly measure tire pressure in cars, and the associated dashboard warning lights, have caused me minor amounts of grief. In our two family cars, even when the tire pressure is fine, the dashboard light for low tire pressure is illuminated perhaps 70% of the time. And in the spring and fall when the temperature is constantly changing, that number is at least 90%. As I write this, the light has been on in both of our late-model cars for over a month straight. And the tires are full and fine. (The dealer and I check.)

The entire system seems poorly designed and/or implemented, and hyper-sensitive. (pic via Automobile)

It’s a constant and unnecessary chicken-little cry about non-existent tire pressure problems. So why would the auto manufacturers all implement such a troublesome annoyance?!

[ Update 12.7.11: Tire Sensors Can Be Easily Hacked ]

Then I learn today via JohnDCook, that the cause of my woes is all-too-familiar. No surprise, though I’m embarrassed I didn’t suspect it, I can thank the federal government and the NHTSA.

[Remember what I said about laws with clever names and acronyms?]

It turns out that both of our cars have this wonderful little system thanks to the TREAD Act. Yes, that’s right, as in tire treads.

Transportation Recall Enhancement, Accountability and Documentation Act – Wikipedia: The Transportation Recall Enhancement, Accountability and Documentation (or TREAD) Act is a United States federal law enacted in the fall of 2000. This law intends to increase consumer safety through mandates assigned to the National Highway Traffic Safety Administration (NHTSA). It was drafted in response to fatalities related to Ford Explorers fitted with Firestone tires, and was influenced by automobile and tire manufacturers as well as consumer safety advocates. After congressional hearings were held in September 2000, Congress in only an 18 hour span passed the TREAD Act in October 2000. The Act was signed into law by President Clinton on November 1, 2000, and has been incorporated into the existing National Traffic and Motor Vehicle Safety Act of 1966, codified at 49 U.S.C. §§ 30101-30170.

Oh, and here’s the original item that got me started on this rant.

No. 2755: Tire Pressure: The late nineties saw a rash of highway fatalities when Firestone tires failed on Ford Explorers. Congress responded by passing the TREAD Act, a provision of which required all new cars to include tire pressure monitoring systems. Full compliance was achieved by 2008. … Common to all pressure monitoring systems is the warning light found on a car’s dashboard. If a tire’s pressure is low, the light will stay on until the problem’s fixed. Since tires tend to deflate a bit over time, we’ll be seeing a lot more people at the air pumps — people who may be dismayed by the inconvenience.

Additional links:
One-Third of Drivers Have No Clue What This Symbol Means, Says Study
TREAD_Act_Summary.pdf