THE FEDERAL HIGHWAY program -- long the pride and joy of those in Congress who delivered impressive roads and bridges to their constituents -- with Uncle Sam picking up most of the tab -- is in visible trouble. Highways and bridges are crumbling, and costs of building and repairing have soared. That is why Transportation Secretary Drew Lewis has been pressing for the better part of two years to win approval of a plan to do something about it.

His plan involves the gasoline tax, but since talk of any tax increase is not the stuff of White House policy discussions, it is best referred to as an increase in a federal "user fee" or -- try this -- a "revenue enhancement" idea. Whatever you call it, it is needed. The present federal tax of four cents a gallon hasn't been changed in decades. Even members of Congress who in an election year are wary of tax increases have been supporting this one and looking to the White House for approval.

"It's very clear," Mr. Lewis notes, "that either through a highway user fee, or general fund taxation, or the states' assuming the responsibility -- which I don't think they can do -- somebody's going to have to address the infrastructure for highways, bridges and mass transportation." He proposes that four cents of a five-cent-per-gallon increase be pledged to highway programs. The other penny would go for transit capital financing.

That's a sensible plan, though it would be better still if instead of a five-cent or money-amount increase, the gasoline tax were set at a percentage of the gallon price. Otherwise, the relative amount of revenue diminishes with inflation -- which is part of the problem already.

In any case, the proposal is practical and politically defensible. White House support can and should deliver this relief if the administration is serious about transportation across the country.