From Obihiro (Odori North-1 intersection) to Makubetsu (Akeno intersection): Route 242
From Urahoro (Yoshino-Kyoei intersection) to the terminus: Route 336
From Shiranuka (West-1 South-2 intersection) to Kushiro (Otanoshike intersection): Route 392
From Kushiro (Kitaodori-5 intersection) to the terminus: Routes 44, 272 and 391
References
^"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 19 February 2020.