U.S. District Court Judge Oren R. Lewis in Alexandria yesterday told the Virginia highway department it can proceed with construction of Interstate Rte. 66 between the Capital Beltway and the Potamac River.

Lewis' ruling, which affirms the decisions of two Secretaries of Transportation to build the 9.7-mile, four-lane highway, was immediately appealed by a contigent of citizen's groups who have sought for years to block construction of the $170-million road.

Leo Bussi, the highway department's director of administration, said a decision would be made Monday on whether to start construction, but he added that it was doubtful that construction would start Monday.

He said highway commissioner John E. Harwood would make the decision after reviewing Lewis' 10-page ruling. He said contractors could begin construction within 24 to 48 hours after Harwood's approval, but Bussi added "I assume (the civic associations) will appeal . . . and get an injunction preventing construction."

Lawrence Latto, an attorney of the Arlington Coalition on Transportation, the chief anti1-66 group, said Lewis' decision was "hardly a surprise. Judge Lewis fairly well indicated at the trial two-weeks ago what he expected to decide."

Latto said he expected Lewis to deny the injunction that was filed by the coalition immediately after Lewis deicision Latto said the group of citizens' organizations would then seek an injunction to block the highway from the U.S. Fourth Circuit Court of Appeals in Richmond.

"I'm certain he'll be reversed on appeal again," Latto said. Lewis approved a wider version of 1-66 five ago, but the Fourth Circuit ordered that new environmental hearings be held by the highway department on it plans. The result is a proposed four-lane jhighway that would be limited to car pools and buses during rush hours and ban trucks altogether.

The suit by the group of civic associations is the latest in a 20-year series of actions mounted by opponents of construction of the road on environmental grounds. The D.C. government also opposes construction on grounds that the link between the Theodore Roosevelt Bridge and the Beltway will further aggravate parking and congestion problems in the Distict.

However, the highway department is firmly committed to completion of 1-66. Last January former Transportation Secretary William T. Coleman Jr. ruled that the road could be completed. In February, Transportation Secretary Brock Adams upheld Coleman's ruling.

The suit filed by the civiv associations claimes that Coleman's ruling was, in the words of Latto, based on an "inadequate and improperly prepared" environmental impact statement. The suit also charged that Coleman's approval was granted in exchange for a political deal with Virginia Gov. Mills E. Godwin to make funds available for Metro construction in the 1-66 median.

In his decision, Lewis wrote, "The Secretary (Coleman's) 71-page decision is quite exhaustive . . . The court finds that the Secretary made a good faith judgement after considering all relevant factors . . . The plaintiffs' charged of unlawful political pressure is too nebulous to warrant discussion."

Lewis said that Coleman "acted within the scope of his authority" and that his decision "was neither arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law."