1. A collision position predicting device comprising: moving object detection unit to detect a moving object on a road; and collision position predicting unit to predict, upon detection of a moving object crossing the road by the moving object detection unit, the collision position of the moving object and the subject vehicle based on a moving vector of the moving object, wherein in cases where the moving object crossing the road into which the subject vehicle has entered is detected at the time when the subject vehicle has turned to the right or to the left, a moving vector calculated from position information on said moving object is decomposed into a road direction component in the direction of the road into which the subject vehicle has entered and a vertical direction component which is vertical to said road, and said vertical direction component is used as the moving vector of said moving object which is used for the prediction of the collision position by said collision position predicting unit, and wherein in cases where a pedestrian crossing is formed on the road into which the subject vehicle has turned to the right or to the left to enter and the moving object crossing the road detected by said moving object detection unit exists on said pedestrian crossing, a moving vector calculated from position information on said moving object is decomposed into a pedestrian crossing direction component and a vertical direction component which is vertical to said pedestrian crossing, and said pedestrian crossing direction component is used as the moving vector of said moving object which is used for the prediction of the collision position by said collision position predicting unit in preference to the vertical direction component with respect to said road into which the subject vehicle has entered.