Final answer:
The shape of a route sign indicates the type of route a driver is on, using standardized shapes to differentiate between interstates, state routes, and local highways.
Step-by-step explanation:
The shape of a route sign is designed to convey information about the type of route you are on, not the speed limit or to suggest that a route might be hazardous. There are different shapes for various types of roads such as interstates, state routes, and local highways. For example, an interstate route sign is often a shield shape, whereas a state route might be a circle, and a local highway may have a different shape. These standardized shapes help drivers navigate and understand the types of roads they are traveling on without reading the details of each sign.