This chapter deals with the bridge as structural element. Single span bridges, two-span and three-span
bridges, arched bridges, cable-stayed and suspension bridges are analyzed in detail regarding their bending and
torsional vibration. The most important relations for studying single cable vibration, harp and fan type cable
systems with dense or not arrangement of cables as well as the curved in plane bridges are presented. The
determination of modal shapes for some characteristic cases of bridges is also given in detail.