A tramway transit system for allowing a vehicle to travel along a track while automatically steered is proposed, in which the vehicle is provided with guard wheels and the track is provided with a protection track, and simplification in construction and weight saving of the automatic steering mechanism provided to the vehicle and space saving for the installation of the mechanism, can be attained. The vehicle (12) is provided with a steering mechanism (26) for steering the front and rear wheels (20, 22) by means of electrically driven oil hydraulic actuators 36, the protection track (14) is laid down on the road surface (15) of the track (01), the vehicle (12) is provided with guard wheels (40), and the interlocking mechanism (48) for connecting the guard wheels to the right or left wheels, the actuator (36) comprising the hydraulic cylinder (60), the two-way discharge pump (76), the variable speed, reversible rotation motor (78), and the closed circuit (82) provided with relief valves (86).