Overview: Welcome to the world's longest worksite —thirty- five miles long. Right now, Switzerland's government is spending $18 billion to revolutionize European transit, using the world's largest Tunnel Boring Machine to build the longest tunnel in history — the Gotthard Base Tunnel. Connecting from Southern Germany to Northern Italy, the GBT will circumvent the winding mountain passes that serve as the current transit system, getting people and goods across the Alps up to 3 times faster, and safer than ever before.