Detour and Ring road

Detour noun - A turning away from a course or standard.

Ring road and detour are semantically related. in roundabout route topic. In some cases you can use "Ring road" instead a noun "Detour".

Ring road noun - A highway that encircles an urban area so that traffic does not have to pass through the center.

Detour and ring road are semantically related. Sometimes you can use "Detour" instead a noun phrase "Ring road".