HOW HIGH the HOV? That is the question.

HOV is highway talk for "High Occupancy Vehicle," and HOV-4, as annoyed Virginia commuters know only too well, is a requirement that you have four people in your car to use the extension of I-66 in and out of Washington at peak traffic hours. HOV-4 is a bust. Not enough people can or do qualify. Too many people jam the shoulders at the ramps to this strip, waiting for the signal ending official rush hour. Fortunately, there is new pressure for relief.

Virginia Sens. Warner and Trible and Rep. Wolf have urged Gov. Robb to give HOV-3 a try. Why not? It can't be any worse than the daily mess created there now. It may well be that three is a workable combination for more motorists and their passengers than four has been. That could mean that the total number of people moved on this strip would increase, which is supposed to be one of the objectives of the HOV policy in the first place.

The three legislators have some other good suggestions: that the state help Northern Virginia areas create "staging areas" where commuters could find passengers for car pools; that the hours of the restrictions be shortened somewhat, and that consideration be given to exempting handicapped drivers from the pool rules.

Maybe, as Virginia highway officials insist, all of the above would misfire. But no one can know for sure without a test.