In vehicle distance warning systems using fixed beam laser radar false alarms often occur on curved roads. To solve these problems, we attempted to detect the target vehicle correctly by using a scanning laser radar on curved roads. This scanning laser radar has the advantage that it is able to measure the distance and direction of obstacles on roads.In this paper, we explain the following three items. The first is the configuration of the experimental system which we developed. The second is the method of target vehicle detection by using reflectors located along roads. The third is the performance of this experimental system.