U.S. District Court Judge Oren R. Lewis yesterday removed the last legal obstacle to construction of Interstate Rte. 66 inside the Capital Beltway by dissolving a 4-year-old injunction requiring compliance with certain requirements.

A Virginia Highway Department official said later that construction of the highway through Fairfax and Arlington counties to the Theodore Roosevelt Bridge could begin in two months.

The Arlington Coalition on Transportation, which originally obtained the injuction and has fought the project for six years, did not contest the bulk of the order to dissolve the injunction, which was prepared by the Justice Department. But, according to Lawrence J. Latto, an attorney for the coalition, the organization is preparing another suit seeking to halt I-66 construction.

The 1972 injunction, signed by Judge Lewis in Alexandria, required that before construction could begin public hearings had to be held, an environmental impact statement made, and the Secretary of Transportation had to decide whether the road could be built.

"We are not here to retry I66," Judge Lewis said at one point during yesterday's hour-long hearing. "It seems to me if they have done A, B, C, D, they can proceed to build it."

The last requirement of the injunction was met on Jan. 5 when then Secretary of Transportation William T. Coleman Jr. approved construction of a four-lane version of I-66.

Coleman required Virginia Gov. Mills E. Godwin Jr. to transfer about $30 million in highway funds to Metro and to complete construction of the I-66 median strip so Metro rails could be laid with the least expense.

Coleman also said that access to the highway must be restricted during rush hours to car pools, buses, emergency vehicles and those bound for Dulles Airport. Heavy trucks are permanently barred and the appearance should be similar to that of the George Washington Parkway.

The decision also requires Virginia to "provide assurances" that jobs and training for minorities will be provided.

New Secretary of Transportation Brock Adams concurred with Coleman's decision last month.

Immediately after Lewis signed the order dissolving the injunction, the Virginia Highway Department asked for permission from the Federal Highway Administration to begin advertising for construction bids on the project, said according to P. B. Coldiron, highway department director of engineering. The highway department could not act until Lewis signed the order, Coldiron said.