Introduce an approach to detect information about lane and vehicle for driver assistance, or lane change assistant system. Most previous research works could only detect the lanes or vehicle separately. However, the combination of lane information and vehicle information is able to support the lane keeping system, or lane change system, and to improve the reliability of results. For lane change assistant system (LCAS), it must detect frontal lanes and discover other vehicles around the host vehicle. Therefore, in this study, we use a vision system including three cameras, two of them are installed under the right and left wing mirrors, the left one is equipped on the windscreen of the host vehicle. Images from the camera are used to detect three lanes, and detect multiple vehicles.