A first acquisition unit acquires the current position of a carriage unit as information regarding the travel environment of the carriage unit. A second acquisition unit acquires a first upper limit value of the travel speed as appropriate travel conditions of the carriage unit corresponding to the current position acquired by the first acquisition unit. A third acquisition unit acquires a first measurement value of the travel speed as information regarding the travel state of the carriage unit. A travel state correction controller performs travel state correction control to make a correction to a travel state satisfying the appropriate travel conditions in a case where the travel state acquired by the third acquisition unit deviates from the appropriate travel conditions acquired by the second acquisition unit. That is, the travel state correction controller reduces the travel speed of the carriage unit in a case where the first measurement value exceeds the first upper limit value.