Car owners shouldn't count on Governor Casey's new auto insurance law to deliver lower premiums this year. Look at what happened last year when the Casey administration "eliminated" sex discrimination.

Starting March 1, 1989 young women were hit with big premium increases that make them pay double what young men pay per mile for insuring their cars.

Women with "adult" class cars are overcharged the same way because insurance premiums aren't tied to miles actually driven and, at every age, women average half men's annual mileage and exposure to risk of accidents.

Whether it's fraudulent "unisex" for young drivers or "adult" for the rest, pricing that overcharges most women is sex discrimination.

Governor Casey could have done an honest job of ending sex discrimination by having premiums tied to each car's on-the-road exposure.

How? By ordering insurers to convert each class rate -- defined by territory, car type, etc. -- from dollars per year (say, $900 per year) to cents-per-mile (say, 9 cents per mile), as used for some commercial vehicles. The odometer is the car's expourre meter.

Besides providing genuine unisex rates that don't overcharge women, meter insurance coverage:

-- allows consumers to control their insurance expenditures to the same extent they can control expenditures for gasoline.

-- provides for the first time a valid statistical baseline for meaningful cost comparisons among territories and other risk classifications.

-- ties premiums to driving and prevents insurer windfalls when driving decreases for any reason.

-- provides direct economic incentive to drive less and use public transit or van pools more. Air quality and energy conservation would benefit.

The fatal flaw in Governor Casey's new law is that promising everybody a discount does nothing to end cost-shifting. Owners of cars driven fewer miles than average for their class should not have to subsidize the cost of insuring cars driven more than than the class average.

Our representatives in Harrisburg can guarantee everyone premiums based on individual costs by adding one sentence to the Rate Regulatory Act: "For driving coverages of private passenger automobiles, the exposure unit shall be the mile as recorded on the odometer of the insured car."

Like gasoline or electricity, auto insurance is too expensive not to meter.