Guide signs logo, indicating the direction of the road and into the inside lane road information to guide the effect is more intuitive, the driver simply select the corresponding national highway driving can be. The current situation is not complicated cross the road side, the guide signs will indicate a more streamlined way to remind motorists to continue to pass or change lanes in advance. Blue background guiding signs usually associated with urban roads, whereas the directional sign with green background urban freeway and highway-related, there is no difference between the two background sign on functionality. Due to the passage from the city's freeway and highway farther, road speed faster, and therefore, the green background guide signs will appear more distance information, and advance guide signs over blue background more distance settings. On urban freeway and expressway guide signs are very common green background, which in addition to the location and direction information, there are more precise distance information to help determine the way ahead in the direction the driver.