The National Bank Park Service has announced it will pave several sections of the bicycle trail along the George Washington Memorial Parkway this spring, and in the fall will extend the trail as far north as Roosevelt Island.

In a companion construction project, Arlington County is now completing plans for a bike bridge over the parkway near Roosevelt Island, which will link county bicycle trails to the parkway and downtown Washington.

A Williamsburg consultant to the country is expected to have plans within the next 30 days for a 10-foot-wide pedestrian-bike bridge at one of three sites just north of Roosevelt Bridge. Final plans, an environmental report and a public hearing on the project are scheduled for late spring or early summer, according to county engineering and design supervisor Lin Lemon.

The cost of the bridge and bike path into Rosslyn is expected to exceed the $250,000 Arlington appropriated for the bridge several years ago. The county is now applying for a state-federal subsidy.

The paving of more than four miles of parkway bike trail follows numerous complaints from bicyclists who have been injured in falls on the narrow, uneven gravel trail. More than 200,000 cyclists a year have been using the bike trail, as well as thousands of joggers, since it was extended to Mount Vernon several years ago. The original section between Alexandria and Washington was completed in 1972. It was paved last year, as was a major section of new trail near Fort Hunt.

The Park Service has left contracts for more than $200,000 to pave the remaining four miles of gravel path. The first section, between Mount Vernon and Waynewood, near Fort Hunt, will be paved in early March, according to parkway Superintendent Don H. Castleberry. The second section, between Waynewood and Alexandria, will be paved later this spring, Castleberry said, with the entire project to be completed by June 1.