AlpTransit
AlpTransit, also known as New Railway Link through the Alps NRLA (German: Neue Eisenbahn-Alpentransversale, NEAT), is a Swiss federal project for faster north-south rail links across the Swiss Alps by constructing base tunnels several hundred metres below the current tunnels. For safety, all the tunnels have two parallel single-track bores joined about every 300 metres with cross cuts, enabling the other tunnel to be used for escape.
Read more about Alptransit.