[3] The expressway was originally built and managed by Japan Highway Public Corporation.

[4][5] The route of the expressway runs through the central part of Nagano Prefecture.

From the origin at a junction with the Chūō Expressway in the city of Okaya near Lake Suwa, the expressway follows a northerly course to Matsumoto, the major city in the central Nagano area.

From here the expressway follows a winding northeasterly course through mountainous areas before reaching the terminus in the city of Chikuma.

Beyond the terminus, the roadway continues as the Jōshin-etsu Expressway towards the city of Nagano, the prefectural capital.