A reversing assistance device suited for a mining dump truck measures a first distance to a first object, which exists at a first height comprising a trajectory of a rear wheel of the dump truck during reversing, and a second distance to a second object, which exists at a second height comprising a trajectory of a vessel during the reversing, for computing the position of the first object. If the distance between the position of the first object and a designated loading position designated by an operator of a loading machine is equal to or smaller than a threshold, the first object is determined to be an approachable object, a smaller one of the first distance and the second distance is determined as a target stop distance, and based on the target stop distance, a target stop position is computed.