Talk:List of longest subway tunnel sections

	This article is within the scope of WikiProject Bridges and Tunnels, a collaborative effort to improve the coverage of bridges and tunnels on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Bridges and TunnelsWikipedia:WikiProject Bridges and TunnelsTemplate:WikiProject Bridges and TunnelsBridge and Tunnel articles
High	This article has been rated as High-importance on the project's importance scale.

Civil engineering High‑importance

	Engineering portal This article is within the scope of WikiProject Civil engineering, a collaborative effort to improve the coverage of Civil engineering on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Civil engineeringWikipedia:WikiProject Civil engineeringTemplate:WikiProject Civil engineeringCivil engineering articles
High	This article has been rated as High-importance on the project's importance scale.

Trains: Rapid transit High‑importance

Trains Portal

This article is within the scope of WikiProject Trains, an attempt to build a comprehensive and detailed guide to rail transport on Wikipedia. If you would like to participate, you can visit the project page, where you can join the project and/or contribute to the discussion. See also: WikiProject Trains to do list and the Trains Portal.TrainsWikipedia:WikiProject TrainsTemplate:WikiProject Trainsrail transport articles

High

This article has been rated as High-importance on the project's importance scale.

Associated projects or task forces:
/
	This article is supported by WikiProject Rapid transit.

Lists High‑importance

	This article is within the scope of WikiProject Lists, an attempt to structure and organize all list pages on Wikipedia. If you wish to help, please visit the project page, where you can join the project and/or contribute to the discussion.ListsWikipedia:WikiProject ListsTemplate:WikiProject ListsList articles
High	This article has been rated as High-importance on the project's importance scale.

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.

What is the cut-off?

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.