A symphony bridge or bridge symphony is a bridge which combines the structural support systems of a suspension bridge, a cable-stayed bridge and a cantilever bridge. No such bridges have been built, nor are there any specific plans, although the method has been considered for several bridges in Norway. It was developed collaboratively by the Norwegian Public Roads Administration and the civil engineering consulting company Aas-Jakobsen as a means of building bridges with spans between 1,000 and 3,000 meters (3,300 and 9,800 ft).