Because the U-shaped highway is relatively curved, and the roads on both sides are inclined inward, if you stop, it is easy to cause the vehicle to lose its balance and even slip off the road, which is dangerous to yourself and other drivers. In addition, U-shaped highways are generally used in mountainous areas or bends, and the pavement is relatively narrow. If you stop, it will occupy the driveway, which will make other vehicles unable to pass and lead to traffic congestion. Therefore, we must abide by traffic rules, respect traffic signals and signs, keep the distance and speed of vehicles, ensure the safety of ourselves and others and avoid traffic accidents.