What do the shape and color of route number signs indicate?

The shape and color of route number signs play a crucial role in identifying the type of roadway and its classification. Each type of roadway—whether it be interstate, US highways, or state routes—utilizes a distinct shape and color. For example, interstate highways are represented by a shield shape with a blue background and red borders, while US highways have a similar shield shape, but typically use a black and white design. State routes generally have a rectangular shape with a green background. This visual differentiation helps drivers quickly understand the type of road they are on and the associated regulations or characteristics, such as driving conditions or speed limits that may apply.

Understanding these signs is important for safe navigation, especially when traveling through unfamiliar areas. It allows drivers to make informed decisions about their route and ensures they are adhering to the rules for different types of roadways.