The Red Line is a rapid transit line of the Washington Metro system, consisting of 27 stations in Montgomery County, Maryland, and Washington, D.C., in the United States. It is a primary line through downtown Washington and the oldest and busiest line in the system. It forms a long, narrow "U," capped by its terminal stations at Shady Grove and Glenmont.
Trains run every 5 minutes during weekday rush hours, every 6 minutes during weekday off-peak hours and weekends, and every 10 minutes daily after 9:30pm.[1]
The Red Line is the only line in the system that does not share its tracks with another Metrorail line. However, it operates parallel to CSX Transportation freight trains along the railroad's Metropolitan Subdivision from the D.C. neighborhood of Brentwood north past Silver Spring, Maryland, and continuing through Twinbrook.