National Route 231 is a national highway of Japan connecting Kita-ku, Sapporo and Rumoi, Hokkaido in Japan, with a total length of 129.2 km (80.28 mi).

References

  1. ^ "一般国道の路線別、都道府県別道路現況" [Road statistics by General National Highway route and prefecture] (PDF) (in Japanese). Ministry of Land, Infrastructure, Transport and Tourism. Retrieved 18 February 2020.