What types of common traffic road signs are there?

City Traffic Guide Directions: Typically, they are square in shape, with a cream color on a deep blue (green) background, featuring cream-colored images. They are used to indicate boundaries between cities and villages, directions and intervals to stations, road entry points, service addresses, and landmarks, etc., along with various directions along the route. This includes such markers as route numbers, milestones, 100-meter posts, boundary posts, road signs, crossroads, road entries, gas stations, maintenance stations, and underground parking garages. Auxiliary signs help attach to the main sign and serve a filling function. They can be categorized into refrigerated truck types, time markings, and spacing sizes. Auxiliary signs should not be set separately.
　　
2. Traffic Signs: Typically circular, square, in deep blue and cream colors. Used to indicate the proper direction and address for vehicles and non-motorized vehicles to follow the rules, such as straight ahead, left turn, right turn, parking, and detour.
　　
3. Traffic Warning Signs: Typically, equilateral triangles (or rhomboids) with a light yellow background and gray-black edges, featuring gray-black images. These signs are used to alert drivers of potential dangers ahead and the necessary precautions to take. Examples include intersections, road curves, railway crossings, slippery surfaces, rocky roads, uneven terrain, and urban traffic convergence points.
　　
4. Urban Traffic Control Signs: Typically circular, with a cream base and red border, featuring a crimson diagonal pattern on gray and black. These signs are designed to restrict or appropriately limit vehicle movement based on street layout, route, and urban traffic conditions. Examples include restrictions on urban traffic, parking, speed limits, gross weight limits, and total width limits.
　　
When setting road traffic signs, they must not exceed the scale of the route and construction. The column length should be approximately 25 centimeters, with directional indicators placed at a ground height of about 150 centimeters, which should be adjusted according to driving conditions. If the route situation differs from the previous one, the road traffic sign posts should be immediately changed and adjusted. Signs should be cleaned and maintained regularly to ensure accuracy.