Norway is constructing the world’s deepest and longest underwater road tunnel, a $2-billion engineering mega-project that will let vehicles drive 1,300 feet below sea level. Once complete, it will transform coastal travel by cutting dangerous routes through fjords and mountains. • The Ryfylke and E39 tunnel systems are being built through solid rock beneath powerful Norwegian fjords. • Drivers will travel more than 27 kilometers underground, beating all previous underwater road tunnel records. •