Concrete can tolerate much more force that previously believed, which
could open the door to a new kind of road structure: a floating tunnel.
The E39 is a nearly 1100-km long coastal road that crosses seven major
fjords by use of ferries. Norwegian authorities are working to improve
the road by eliminating ferry crossings, which in addition to being
costly, mean that drivers have to wait for ferries if they don’t arrive
at the crossing at exactly the right time. Norwegian engineers are
examining an entirely new type of water crossing: submerged
floating tunnels.