Bogie angle linked steering trucks have an excellent curving performance in circular curve sections. In order to gain even greater curving performance, a power-assisted steering system was developed for reducing wheel lateral forces in transition curve sections by generating the control force in the turning direction of the steering truck. In addition, a steering electro-hydraulic actuator was designed for reducing lateral forces in transition curve sections while preventing wrong direction steering operation which is the biggest problem with active steering systems. Finally, confirmation was obtained through running test on a test line that this steering actuator improved steering performance and maintained the fail-safe function.