This paper explains the effectiveness of camera images in reducing accidents when changing lanes. A Side View Camera shows images rearward and to the side that include the blind spots of side-view mirrors on an onboard display. The effectiveness of a rear-view camera for parking at low speed is well-known, but little has been verified on the effectiveness of the camera for changing lanes at high speed on a freeway. We used a driving simulator to verify the effectiveness of camera images to assist the driver to confirm safety. The simulator reproduces various dangerous scenes a driver may encounter when changing lanes in a freeway environment. The accident rate when drivers change lanes using common methods, such as the driver looking over his or her shoulder and checking the side-view mirror, were compared with the addition of images from the Side View Camera that offered the same view as the side-view mirror plus the blind spot displayed on an in-vehicle monitor. We found that using Side View Camera was more effective for reducing the accident rate when changing lanes than using side-view mirrors only.