This paper reviews the state-of-the-art of semi-active and active suspensions for use in ground transportation vehicles and compares their performances to conventional suspension. The evolution of active and semi-active suspensions from theoretical and analytical consideration to application is presented.The primary focus of the paper is on ride quality control. The section on theoretical considerations summarizes the results of a multi-degree of freedom (MDOF) vehicle models. The paper investigates analytically, the use of active and semi-active suspensions for ride quality. It is shown that the separate control structures using different measurements and actuator are effective in controlling ride. Generally speaking, an active suspension system is required to optimize between ride comfort and road handling, between soft and firm ride. It is shown in this paper that improved performance is coupled with increased hardware complexity and higher costs.A section on a survey of current application of semi-active and active suspension in North America and around the world is presented. Finally, a concluding section indicates future trends in semi-active and active suspension applications.