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.