[Windflier]

How deep is this tunnel? I thought that it was for a road... how are drivers going to get through it if they'll need time in a decompression chamber after driving through?

Consider that the NY Times is the source of that comment.

[Axenolith]

Yea, the tunnels are usually pressurized to keep water to a minimum.

[Elsiejay]

“might have to work “at atmospheric pressures similar to what a diver would experience,” the New York Times adds, and even spend “time in a decompression chamber” on their way back up to the surface, to find out.”

That’s cuckoo!! They’re not working submerged in a fluid (i.e., water). Its not unlike working deep in a mine.