The total projected cost of the project was CHF 12.189 billion at its 1998 start; in December 2015, its final cost was projected to be CHF 17.900 billion. The 1998 projected total cost of the Gotthard Base Tunnel was CHF 6.323 billion; in December 2015, its final cost was projected to be CHF 9.560 billion. It opened on 1 June 2016, and became operational on 11 December of that year. The Ceneri Base Tunnel was opened on 3 September 2020 and became fully operational in December 2020 and is an important feeder for the Gotthard Base Tunnel. Work on the completion of the second tube of the Lötschberg Base Tunnel is expected to start in 2021/2022 for a targeted opening towards the end of 2028.