How many classifications of highways are there according to the given material?

In the context of highway classification, the correct classification is three. Highways are generally categorized based on their function and characteristics, which typically include rural highways, urban highways, and limited-access highways. Each of these classifications serves distinct purposes and has specific design features that cater to different types of traffic and road use.

Rural highways facilitate longer-distance travel and connect smaller towns, urban highways are designed for traffic within city areas, and limited-access highways, such as interstates, are constructed to allow vehicles to enter and exit at designated points for efficient high-speed travel. Understanding these categories is crucial for drivers as it informs them about road types and the associated rules and regulations in various driving conditions.