This is a four span bridge, which is prestreesed in four dimensions, and runs over a number of railway lines. The design has been awarded a number of prizes. The axis of the bridge is circular, and consequently the weight of the bridge imposes torsional moments on the structure. The most original feature of this project is the placing of the prestressing along three space coordinates, and also the regulation of the prestressing forces as functions of time. The prestressing is very densely distributed along the curved part of the structure. This counteracts the effects of the dead weight, and enables the structure to be statically considered as if its spans were straight. Owing to the large torsional moments, the bridge consists of seven T section beams, to reduce the weight and the number of prestressing cables. Another interesting feature of this design is that the springers have been readjusted 25 cm, in order to regain the original compressive constraints, which would have been lost in time, due to creep phenomena. Precast units were not used, as they were not the most apt to work under torsion, and for similar reasons only two dilation joints were fitted.