Reading Chinese Road Signs by Shape and Color

Warning signs are triangular with a red border. They tell you something requires attention ahead.

Prohibition signs are circular with a red border. They tell you what you must not do.

Instruction signs are circular with a blue background. They tell you what you must do.

Guide signs are rectangular. Blue generally indicates urban roads, green indicates expressways.

Once you can classify a sign by shape, the text inside becomes secondary, which is why this method works well for non-Chinese readers.