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Text and/or other creative content from this version of List of long tunnels by type was copied or moved into List of longest subway tunnel sections with this edit on 11:09, 1 June 2016‎. The former page's history now serves to provide attribution for that content in the latter page, and it must not be deleted as long as the latter page exists.

The current shortest subway tunnel length listen on this page is about 13km. At what tunnel section length should we stop listing subway tunnel sections as being the longest? 13km? 15km? Perhaps even 20km just to cut out the less noteworthy lengths of underground trackage? Of course this is all rather arbitrary but something to keep in mind.