What is the purpose of route signs and markers?

Route signs and markers serve to provide crucial information regarding U.S., interstate, or state route numbers. These signs help drivers navigate the roadways by clearly identifying the routes they are on, assisting in navigation and trip planning. Knowing the route numbers can be particularly useful for understanding where a road leads, which areas it connects with, and how it fits into the larger network of highways and roads. For instance, drivers can use route numbers to identify connections to major cities or other significant destinations.

The other options relate to different types of signage. While local traffic laws could be indicated by other signs, they are not the primary purpose of route markers. Signs showing directions to hospitals serve a separate function, focusing on emergency services rather than navigation of routes. Indicating construction zones is also a different category as it pertains to temporary changes in road conditions and safety warnings for drivers, not the identification of route numbers.