AlpTransit

thumb|upright=1.4|alt=Rail map of Switzerland and surrounding countries|The NRLA project is the centrepiece of the Central European rail network. The New Railway Link through the Alps (NRLA; , , ), is a Swiss construction project for faster north–south rail links across the Swiss Alps. It consists of two axes with several improvements along these rails including three new base tunnels several hundred metres below the existing apex tunnels, the Gotthard Base Tunnel, the Lötschberg Base Tunnel, and the Ceneri Base Tunnel. Swiss Federal Railways subsidiary AlpTransit Gotthard AG and BLS AG subsidiary BLS Alp Transit AG (now BLS Netz AG) were founded for this project and built the tunnels.

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. A decision to fully complete the second tube of the Lötschberg Base Tunnel was made in early-2024, with an estimated cost of CHF 1.7 billion. Construction is expected to extend from 2026 to 2033.