Apparently the combination of bridge and tunnel to cross a body of water has been used quite successfully in several places: https://en.wikipedia.org/wiki/Brid

Apparently the combination of bridge and tunnel to cross a body of water has been used quite successfully in several places: https://en.wikipedia.org/wiki/Bridge%E2%80%93tunnel https://en.wikipedia.org/wiki/Bridge%E2%80%93tunnel I don't know if it would have been helpful in this case, though.