THERE'S NO getting around it--or through it: I-66 inside the Beltway is nearly impenetrable much of the time. It is Virginia's longest-nonrunning Study in Still Life, where motor fuel and motorists' tempers burn in tandem. Arlington is home to the fumes and fuming but nonetheless isn't exactly overcome with joy at the prospect of widening this road even by a lane. The Arlington County Board so noted, once again and unanimously, at its meeting Saturday.

The board's resolution calls instead for public transportation and everything but road relief: comprehensive studies of the corridor to consider telecommuting, "live-near-your-work" incentives, express bus service and car-pool rules in both directions at rush hours.

Every incentive to discourage motor traffic is welcome, certainly, but existing volume is horrendous, and nothing in the cards says traffic will diminish over the next 20 years. Alternative routes? They exist, and many motorists are using them already, choking residential streets in Arlington and Falls Church. Some motorists might welcome convenient bus service, but more of them have chores, children and other obligations that can't be handled from a bus.

That is why Congress, the state of Virginia and nearby local jurisdictions support the widening of I-66 inside the Beltway. Virginia Rep. Frank Wolf, who led the congressional charge to allow the change, is not one who believes roads alone must rule. He has pushed for mass transit, parking for bus riders and telecommuting incentives. But the growth of Tysons Corner and the population and technology booms throughout Northern Virginia have put huge pressure on I-66.

The state already owns property needed to widen the highway, Mr. Wolf notes, adding that an extra westward lane could be built without eliminating bike paths or noise walls. The concerns of Arlingtonians--and it's not clear what percentage of the county's residents oppose the widening--should be addressed, but along with planning for road relief. To insist that all other measures be tried and exhausted first is to let mounting traffic troubles pile up to impossible dimensions.