Arlington has more than of on-street and paved off-road bicycle trails. Off-road trails travel along the Potomac River or its tributaries, abandoned railroad beds, or major highways, including: Four Mile Run Trail that travels the length of the county; the Custis Trail, which runs the width of the county from Rosslyn; the Washington & Old Dominion Railroad Trail (W&OD Trail) that travels from the Shirlington neighborhood out to western Loudoun County; the Mount Vernon Trail that runs for along the Potomac, continuing through Alexandria to Mount Vernon. In Fall 2015, Arlington was awarded a Silver ranking by the League of American Bicyclists for its bike infrastructure.