The fact today is that the longest large tunnels in the world is constructed for water distribution, followed by tunnels for railways and metro. The top 10 of all of the tunnels are below with longest to come at the end, starting from number 10.
10- Tochomae - Shiodome - Hikarigaoka (Toei Oedo Line)
|Year||2000 (started in 1991)|
9- Metro Madrid L-12: (Metro Sur)
|Year||2003 (started in 1993)|