It is clear that vehicle appearance with binary image as Figure 8(a). But there are many noise on the road surface. Due to remove small noise, the first step used 3x3 matrix to erosion and dilation, and then used Connected Component Labeling (CCL) to remove non-vehicle noise and calculate the final object of position and aspect ratio and mapped to original image. The process results are shown in Figure 8(b), (c) and (d). If the aspect ratio more than 0.15 or less than 1.3, then continue to detection step, else return to scan line.