If the purpose behind the Transportation Recall En-hancement, Accountability and Documentation (TREAD) Act is to improve tire and vehicle safety, then the recent federal appeals court decision overturning the final tire pressure monitoring rule is a good thing.

Under pressure from the Office of Management and Budget, the National Highway Traffic Safety Administration (NHTSA) issued a final rule earlier this year permitting auto makers to install either direct or indirect tire-pressure monitors on vehicles. It allowed both, despite the fact the two systems are not equally effective in warning drivers of underinflation.

The TREAD Act mandates the use of inflation monitors on some new passenger cars and light trucks beginning Nov. 1.

While any type of pressure-monitoring system is better than none, it's clear that requiring a direct system-which can detect pressure changes of as little as 1 psi-will best achieve the intended result of warning drivers when a tire is low on pressure.

Indirect systems, which rely on the anti-lock brake mechanism to detect differences in wheel rotation caused by tire deflation, are not nearly as effective and could result in vehicles running on dangerously low tires with no warning.

This no doubt is what prompted several consumer groups to sue NHTSA to get the rule reversed.

As Circuit Judge Robert D. Sack wrote on behalf of the three-judge panel: ``Unlike direct systems, which work in virtually every instance in which one or more tires are significantly underinflated, indirect systems do not warn drivers in about 50 percent of those instances. Absent any satisfactory explanation in the rulemaking record, the adoption of a standard that permits installation of plainly inferior systems seems to us to be arbitrary and capricious.''

So now the agency must decide on its next action. It can request a review of the case by the appeals court, take the matter directly to the U.S. Supreme Court or comply with the appeals court's ruling and rewrite the standard.

We suggest it do the last option and also include in the new rule a provision requiring a minimum reserve inflation pressure standard for tires. This is, as the Rubber Manufacturers Association correctly points out, a crucial aspect of the tire-monitoring provision. A minimum reserve standard is needed to counteract the 25- or 30-percent underinflation levels that the monitoring rule would allow.

The ruling by the U.S. Court of Appeals for the Second Circuit in New York has given NHTSA a chance to write a more effective standard. The revised rule should require vehicle makers to install direct tire-pressure monitors and also provide for a minimum reserve standard in tires. Then it will do what the authors of the TREAD Act intended: truly improve tire and vehicle safety.