Salt Lake County is considering installing GPS units in its vehicles to keep track of where employees drive.

Given the county's recent problems, from an elected official who used a county credit card to fill up his personal vehicles to another official who used his county car to haul a boat to Lake Powell, that's probably not a bad idea. The only concern is that government shouldn't get too chummy with the idea of using modern technology to track things.

Today, county employees. Tomorrow, the rest of us.

That's not an entirely far-fetched concern. Oregon recently started a pilot program that could one day lead to all cars registered in the state having GPS systems onboard. Using the satellite technology, the state would be able to track just how far everyone drives and tax them accordingly.

For the most part, people would be taxed for the number of miles they drove, not for how much gas they purchased. But the technology allows for some interesting possibilities. For instance, people who drive during rush hour could be taxed at a higher rate than those who wait until off-peak times. Your particular tax rate would be applied automatically when you filled up at the local mini-mart.

That idea comes laden with a lot of questions of fairness. A poor person who has to drive during peak times would be hit disproportionately hard. And such a tax policy would do nothing to encourage people to buy fuel-efficient cars.

All of which has little directly to do with the county's idea for handling its 2,200-vehicle fleet. There is a definite sweet taste to the idea of making sure all public employees use public property wisely, and the thought that someone back at the county's government center could shut off an engine by remote control if it were driving somewhere unauthorized is especially gratifying.

The only problem there is that a suddenly disabled county car might cause a jam on the freeway. But the resulting public embarrassment would be a strong deterrent.

As long as government uses modern technology to police itself and protect taxpayers, no one should quibble. But a distinct line needs to be drawn between monitoring public servants and monitoring everyone else.