In the paper, we use the vertical Sobel edge detection and a noise filter to solve the problem of by pulse for the tracking mode of lane detection. Since the problem of by pulse is effectively solved, the lane detection accuracy is increased. Furthermore, we can effectively improve the processing speed of lane detection system, by reducing the image space and the elliptical ROI size. In experiment results, the proposed method can effectively solve the problem of by pulse in daytime, night and rain situations. The test video size is 640 × 480. The processing speed is about 55~60 frames per second. Compared with the previous method, the proposed algorithm can speed the processing of frames up to 71%, and the total accuracy is increased from 96.19% to 97.07%.