A committee of the Virginia House of Delegates approved by voice vote today a bill to regulate intrastate commuter buses, such as the Northern Virginia bus that plunged into a creek two years ago, killing 11 people.

The bill was sponsored by Democratic Del. David G. Brickley of Prince William County, where the fatal crash occurred. His bill would require commuter bus owners to keep records of the maintenance they perform, and it would allow state police inspectors to visit garages to inspect those records and the buses themselves.

Interstate bus travel is regulated by the federal government, but intrastate commuter buses in Virginia have only to pass inspections similiar to those given private automobiles. State police currently may stop the buses on the highway, but a police spokesman said it is almost impossible to examine the true condition of a bus except in a garage with a pit.

The commuter bus that drove off Interstate 95 near Quantico, owned by a husband-wife team that performed the maintenance and hired one driver, was found to have a badly worn steering mechanism, Brickley said. He said two other commuter bus crashes in Virginia during the last two years also involved buses made in 1959 or 1960.

The bill now goes to the floor of the House, where the unanimous committee vote and a letter of support from Gov. Charles S. Robb should help its chances.