(a) large buses, tractors, city buses, medium-sized buses, large trucks, ramps, fixed-point parking and starting, side parking, passing through unilateral bridge, curve driving, right-angle turning, passing through width-limiting doors, passing through continuous obstacles, rolling roads, turning around on narrow roads, coping with simulated expressway, continuous steep mountain roads, tunnels, rainy (foggy) days, wet roads and emergencies.