DON'T LOOK NOW -- unless you live within sight of it -- but I66, the last of the red-hotly contested highway strips in the great road plans of the fabulous 50's is, under brand new fire: this time, neighbors of the controversial 9-1/2-mile section being built between the Capital Beltway and the Theodore Roosevelt Bridge are taking a decidedly dim view of the bright lighting that the state has in mind for this section of the highway.

The critics have a point -- up to a point. Plans call for those high-pressure sodium vapor lights that can turn night into day at the flick of a switch. The residents argue that having the Great White Way streaming through their back yards not only would take its toll on property values but also would look awful. Those are not frivolous objections. But the state has another interest: safety. Officials point to all sorts of studies showing that good lighting can mean marked improvements; when lighting was turned off along Shirley Highway between Springfield and the 14th Street Bridge during 1972-73, the accident rate went up 44 percent during the darker days of the winter months and 10 percent in the spring.

Virginia Highway and Transportation Commissioner Harold C. King says research in many other cities have produced similar statistics. He estimates that anyone driving along the unlighted George Washington Parkway at night is four times more likely to be in a fatal or injury-causing accident. That is a strong argument for effective lighting along I66.

But how bright and complete does it have to be? Full lighting along the entire section seems excessive. The emphasis should be on intersections and other danger spots, with softer illumination along other sections. Besides, there is another accident deterrent that has strong backing from the neighbors and should be part of the plans: a speed limit of, say, 45 miles per hour. Surely a compromise can be struck that will meet the objectives of both sides in the battle-weary world of I66.