The International Tunnelling and Underground Space Association (ITA) is the leading international organization promoting the use of tunnels and underground space through knowledge sharing and application of technology. ITA represents all aspects of tunnel and underground space planning, design and construction. Since its inception in 1974, ITA has encouraged the use of the subsurface and has promoted advances in planning, design, construction, maintenance and safety of tunnels and underground space. Currently, ITA is made up of 73 Member Nations and 300 Corporate or Individual Affiliate Members.
ITA holds, at once, its General Assembly Meeting and the World Tunnel Congress (WTC) in a different Member Nation, each year.