Classified according to their usage, tunnels and underground caverns in Taiwan include hydropower tunnels, diversion tunnels, railway tunnels, highway tunnels, mass rapid transit tunnels, and other underground works. The introduction of new tunnelling techniques combined with accumulated experience has enabled Taiwan's tunnelling industry to advance by leaps and bounds in both quality and quantity. Statistics show that by the end of 1995, nearly 500 tunnels of various magnitudes had been completed. This number does not include tunnels constructed for military purposes. The total accumulated length of these tunnels is over 670 km, including 360 km of tunnels that are under construction or planning. The following table presents statistics on tunnels completed since the late 1970's.
 
Major Tunnels and Underground Caverns Completed Since the Late 1970's
Project No. of Tunnels and Lengths
Railway Tunnels
North-Link Railway Project 16 tunnels, total length 31,030m, maximum length 7,740m
South-Link Railway Project 35 tunnels, total length 38,924m, maximum length 8,070m
Urban Railway Underground Project, Taipei 1 tunnel, total length 9,000m
Highway Tunnels
Northern 2nd Freeway 26 tunnels, total length 16,100m, maximum length 1,864m
Hydropower Projects
Feitsui Reservoir Project Total length 1,507m, maximum length 409m
Minghu Pumped Storage Hydropower Project Total length of diversion tunnels 9,606m, maximum length 2,381mOne powerhouse cavern 127m(21.2mW×40.5mH)
Mingtan Pumped Storage Hydropower Project Total length of diversion tunnels 11,614m, maximum length 3,172mOne powerhouse cavern 158m(22.4mW×46.0mH)
New Tienlun Hydropower Project Total length of diversion tunnels 10,846m, maximum length 10,566mOne powerhouse cavern 51m(19.8mW×41.0mH)
Mass Rapid Transit Systems
Taipei Metro System Project Total length 45,771m Sewerage Tunnels
Sewerage Tunnels
Sewerage Projects for Taipei and Kaohsiung cities Total length 28,756m

Total：202km

Schemetic Diagram of Ventilation System for Pinglin Tunnel