Flexible structures (such as long-span suspension bridges which undergo moving load, wind or earthquake excitations) exhibit complex dynamic behavior. Due to high cost of strengthening such structures, as well as the technological advances in recent years, much attention has been given to using innovative means of enhancing structural functionality and safety against dynamic excitations. Among the methods used to mitigate the excessive vibration of structures, the energy absorber systems are more promising. This book presents a comprehensive assessment for linear and nonlinear passive vibration absorbers applied on the beams subjected to transient and successive traveling loads. This book is specially helpful for the companies and researchers who are working on bridges and other structures subjected to moving loads excitation.