The controversial realignment of a two-mile section of the George Washington Memorial Parkway bicycle trail, through the Collingwood section between Alexandria and Mount Vernon, will go before the National Capital Planning Commission next month for final approval.

The relatively minor route change, approved early this past summer by the National Park Service after extensive studies, public hearings, and an environmental impact assessment, was to have been built this fall. It has been delayed by continued opposition from citizen groups and threatened lawsuits.

The 16-mile bicycle route from Memorial Bridge to Mount Vernon, built in 1973, now attracts more than 1,000 cyclists a day on pleasant weekends. It is built almost entirely on Park Service land except where it follows city streets in Alexandria and Park Service and Fairfax County roads in the Collingwood section.

The proposed new route, one of a half dozen originally considered by the Park Service, would put the bike trail entirely on federal land through Collingwood, take it off public streets, and eliminate 11 intersections where bicyclists and motorists now encounter each other.

However, the proposed new route, while on parkway land, would still cross five roads that connect with the parkway. These crossings, which are also on the present bike route, are considered traffic hazards by two Collingwood civic groups. They have hired a lawyer to press their case.

They would like to see the Park Sercice place the bike route entirely along the east, or rifer, side of the parkway, a route the park service rejected because it would require expensive boardwalks along the river. Also, the Park Service says there is insufficient parkland to build a path in some sections on the river side, which would force bicyclists to use narrow, winding counting roads. East side residents objected to the east side bike route, contending it would create traffic hazards along those roads.

The National Capital Planning Commission will consider the Park Service's proposed emendment ot its parkway master plan, which would reroute the bike trail, at either its Dec. 1 or Dec. 8 meeting.