Metropolitan Branch

The Metropolitan Subdivision is a railroad line owned and operated by CSX Transportation in the District of Columbia and the U.S. state of Maryland. The line runs from Washington, D.C. northwest to Weverton, Maryland along the former Metropolitan Branch of the Baltimore and Ohio Railroad.

At its southeast end, north of Union Station, the Metropolitan Subdivision meets the Capital Subdivision (formerly called the B&O Washington Branch) and Amtrak's Northeast Corridor. It meets the Old Main Line Subdivision at Point of Rocks, Maryland, and at its northwest end in Weverton, the line joins the Cumberland Subdivision.

MARC Train's Brunswick Line uses the entire subdivision, as does Amtrak's Capitol Limited. The Red Line of the Washington Metro shares right-of-way with the subdivision along two separate stretches in Maryland and DC: from the junction with the Capital Subdivision to north of Silver Spring, and from south of Twinbrook to the end of the Red Line at Shady Grove.