To enhance riding comfort during constant speed travelling by allowing a travel managing section to collectively transmit control information to a train information management device set to each vehicle.

An operation assisting system includes a high speed operation assisting device 11 outputting a constant speed operation command 8D when vehicle speed 9D reaches a predetermined value, a vehicle control device 9 mounted on one or a plurality of vehicles for controlling the motor 10 torque of each vehicle based on the constant speed operation command 8D, and the train information managing device 8 receiving the constant speed operation command 8D transmitted from the high speed operation assisting device 11. The train information managing device 8 collectively transmits the constant speed operation command 8D to each vehicle control device 9.