A bill to authorize state backing for $57 million in bonds to finance construction of a commuter toll road along the Dulles Interntional Airport right of way got the unanimous endorsement of the Virginia Senate Finance Committee today.

The committee acted despite warnings by Del. Mary A. Marshall (D-Arlington) that the project invites court challenges. She urged delaying action until an environmental impact statement can be filed.

The measure, which would authorize insuring the bonds with the credit of the state, now goes to the full Senate for action. It has been endorsed by Gov. John N. Dalton and the State Highway Commission and is expected to win easy passage.

Marshall said the proposed road alarms patrons of Wolf Trap Farm, the National Park Service's outdoor performing arts center near the present Dulles Access Road.

"The most obvious impact is the impact on Wolf Trap," she said. "I'm sure you are quite aware that a suit will be filed. You're going to hit something worse than environmentalists, you're going to hit art lovers."

Sen. Omer L. Hirst (D-Fairfax), chief patron of the Dulles bond bill, disagreed with Marshall. He told the committee that Wolf Trap officials have acknowledged to him that noise abatement barriers planned for the toll road will reduce current noise levels at the arts park.

Sale of the bonds would finanve construction of four commuter lanes parallel to the Dulles Access Road, now limited to airport traffic.

Backers of the proposed road between the Capital Beltway and the airport say it is needed to relieve commuter congestion and to provide access to 6,000 acres of undeveloped commercial and industrial land in the Dulles corridor.

It is expected that toll revenues will be sufficient to pay off the bonds. However, an estimated $33 million can be saved through lower interest rates on the bonds if the state pledges to pay them off in event of default.

John F. Herrity, chairman of the Fairfax County Board of Supervisors, told the committee that the project has the endorsement of the board and "enjoys almost universal support" throughout the county.