A travel assistance device includes a first rail inclined downward from a first end portion side to a second end portion side in longitudinal direction, a second rail provided parallel to the first rail and inclined, in opposite direction to the first rail, downward from the second end portion to the first end portion in the longitudinal direction, a holding member having a runner portion slidably guided by the rails and holding a travelling body, and a switch mechanism configured to be switched between a state in which the runner portion is guided by the first rail and is assisted to travel downward on the first rail by a load applied to the runner portion and a state in which the runner portion is guided by the second rail and is assisted to travel downward on the second rail by the load applied to the runner portion.