The Boulevard Line (Danish: Boulevardbanen) is a 3.2-kilometer (2.0 mi) long railway line between Copenhagen Central Station and Østerport Station in Copenhagen, Denmark. The quadruple track line carries two tracks of the S-train and two tracks of the mainline railway. It opened in 1917, allowing services on the Coast Line and the Klampenborg Line to extend to Copenhagen Central Station. The line became part of the S-train network on 15 May 1934. The line has two intermediate S-train stations, Vesterport Station and Nørreport Station, although only Nørreport is served by regional trains.
- Larsen, Morten Flindt; Poulsen, John (2009). S-banen 1934–2009 (in Danish). Smørum: Bane Bøger. ISBN 978-87-91434-20-4.
- Larsen and Poulsen (2009): 4
- Larsen and Poulsen (2009): 17
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