WASHINGTON, D.C. — A newly proposed vehicle safety standard would require devices that warn drivers when a tire is significantly under-inflated.

The National Highway Traffic Safety Administration (NHTSA) issued the proposal, which applies to buses, passenger cars, trucks and other vehicles that have a gross weight rating of 10,000 pounds or less, except those with dual wheels on an axle.

If implemented, the new Federal Motor Vehicle Safety Standard would require manufacturers to install a four-tire Tire Pressure Monitoring System (TPMS) that can detect when a tire is more than 25 percent under-inflated. In such a case, the TPMS warns the driver.

The NHTSA proposal would also add a malfunction indicator that would notify the driver when the TPMS is not working properly. However, the administration warned that the TPMS is not a substitute for regular tire pressure maintenance by vehicle operators.

In the first model year that would be affected, which begins Sept. 1, 2005, 50 percent of all light vehicles manufactured would comply, followed by 90 percent a year later. After Sept. 1, 2007, all light vehicles manufactured would comply. To view the proposed rulemaking and submit comments, visit http://dms.dot.gov.