The Rustic Road system is a system of Wisconsin scenic roads. They differ from the main trunkline highway system in that they are not meant to be major through routes, but lightly traveled local access, and are to meet minimum standards for natural features. Rustic roads have lower speed limits than those on other highway systems. Each route is marked by brown and yellow signs, with the route number on a small placard below the sign. The letter "R" prefix is followed by the number designation. Wisconsin is the only state to have a system of rustic roads. Wisconsin has a separate system of scenic byways following the development of a national system in the 1990s.