What type of highway in Wisconsin is indicated with a letter?

In Wisconsin, the type of highway indicated with a letter is the county highway. Each county has its own designation system, which assigns letters as identifiers for these highways. This practice helps easily distinguish county roads from state and interstate routes, which have their own numbering systems. County highways are crucial for providing access to rural areas and connecting smaller towns to larger thoroughfares.

While freeways, state highways, and interstates use numbers for classification, county highways are specifically marked with letters, indicating a unique designation that serves local travel needs. This system facilitates navigation and aids in local road management, making it clear which highways serve county purposes versus those that are state or interstate routes.