A travel unit travels in a curved section in an orientation in which a target wheel comes into contact with a target rail, a guide wheel comes into contact with a guide rail, and a non-target wheel does not come into contact with a non-target rail. The control unit changes the rotational speed of a first wheel and a second wheel in the curved section relative to the rotational speed of the first wheel and the second wheel in a straight section in accordance with the ratio of a second length, which is the length of the target rail along a travel path, to a first length, which is the length of the curved section along the travel path at a center portion in a widthwise direction of the travel path.