In 2000, Congress passed the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act. Section 13 of this Act directed the United States Department of Transportation to complete a rulemaking within one year. This rulemaking requires implementation of a warning system in new motor vehicles to indicate to the operator when a tire is significantly under-inflated.

In support of rulemaking activities mandated by Section 13 of the TREAD Act, the National Highway Traffic Safety Administration’s National Center for Statistics and Analysis conducted the Tire Pressure Special Study (TPSS). The TPSS was designed to assess to what extent passenger vehicle operators are aware of the recommended tire pressures for their vehicles, the frequency and the means they use to measure their tire pressure, and how significantly the actual measured tire pressure deviated from the manufacturer’s recommended tire pressure.

There are two types of Tire Pressure Monitoring Systems (TPMS), direct and indirect. Direct systems operate with a tire pressure sensor in each tire cavity while indirect systems monitor under-inflation by comparing characteristics of tires, e.g. comparing wheel speeds using the anti-lock braking system (ABS). This paper will discuss how the data from the TPSS were used to simulate the effectiveness of an indirect Tire Pressure Monitoring System.