国道406号 | 白馬から菅平高原経由で高崎へ。長野～群馬の裏ルート | 起点（長野県大町市）→ 終点（群馬県高崎市）全線約194km | 車載動画 | GoPro11

Route 406 is a general national highway that runs from Omachi City, Nagano Prefecture, through Hakuba Village, Kitaazumi County, Nagano City, Suzaka City, Sugadaira Kōgen, and Agatsuma County, Gunma Prefecture, to Takasaki City, Gunma Prefecture. It overlaps with many national highways, including Route 18, Route 117, Route 144, Route 145, Route 147, and Route 148. The single section has many curves and narrow roads, which are called "Kokudō (bad roads)". Departure : Route 406 start point (Daikoku-cho intersection = Route 147 and 148 start point) - Ōmachi, Ōmachi City, Nagano Prefecture Arrival : Route 406 end point (Kimigayo Bridge West Intersection = Route 18 intersection) - Shimotoyooka-machi, Takasaki City, Gunma Prefecture Date : Mid-November, 2022 Distance : Approximately 194 km (measured by Google Maps) 00:00:00 Opening 00:02:37 Route 406 start point (Daikoku-chō intersection = Routes 147, 148 start point) - Ōmachi, Ōmachi City, Nagano Prefecture 00:16:40 Yanaba Ski Resort *Not in operation after the 2015-2016 season. Nearest station is discontinued - Taira, Ōmachi City 00:24:10 Roadside Station Hakuba - Kamishiro, Hakuba Village, Kitaazumi County 00:30:19 Route 148 overlap end - Hokujō, Hakuba Village, Kitaazumi County 00:45:07 Shirasawa Pass Observatory (Minekata Pass)/ Shirasawa Tunnel - Kamishiro, Hakuba Village, Kitaazumi County 00:50:18 Setogawa, Ogawa Village, Kamiminochi County 00:53:08 Kinasahikage, Nagano City 01:00:14 Okususobana Onsen Kinasa no Yu *Simple sulfur cold mineral spring - Kinasahikage, Nagano City 01:12:05 Kinasa Tabi no Eki (Kinasa museum, agricultural products shop, soba restaurant, etc.) - Kinasa, Nagano City 01:17:52 Nakamine Tunnel - Togakushi Tochiwara, Nagano City 01:21:18 Soyama Tunnel - Togakushi Soyama, Nagano City 01:26:09 Togakushi Bridge (Susobana River) - Togakushi Soyama, Nagano City 01:37:36 Mosuge Ōhashi Bridge (Susobana River) - Mosuge, Nagano City 01:40:16 Shinshū University, Faculty of Education - Nishi Nagano, Nagano City 01:47:42 Route 18 and 117 overlap section - Higashi Wada, Nagano City 01:52:51 Route 18 and 117 overlap end - Yanagihara, Nagano City 01:53:56 Murayama Bridge (Chikuma River, Ayu River) *The parallel railroad is Nagano Electric Railway Nagano Line - Murayama, Nagano City 02:00:54 Route 403 intersection - Suzaka, Suzaka City 02:27:31 Sugadaira Kōgen, Ueda City 02:35:09 Sugadaira Ōhashi Bridge (Lake Sugadaira) - Sugadaira Kōgen, Ueda City 02:35:38 Sugadaira Dam - Sugadaira Kōgen, Ueda City 02:40:21 Route 144 overlap section - Osa, Sanada-machi, Ueda City 02:48:08 Prefectural border (Torii Pass, Altitude 1362 m): Ueda City, Nagano Prefecture → Tsumagoi Village, Agatsuma County, Gunma Prefecture 02:55:52 Tsutsuji no Yu, *calcium, bicarbonate, and chloride hot spring (neutral hypotonicity hot spring) - Tashiro, Tsumagoi Village, Agatsuma County, Gunma Prefecture 03:00:14 Nariiwa Bridge and roads under restoration due to the East Japan Typhoon Disaster in 2019. 03:04:16 Tsumagoi Bridge (Agatsuma River) - Ōzasa, Tsumagoi Village, Agatsuma County 03:10:32 Manza Kazawaguchi Station (Agatsuma Line) - Kanbara, Tsumagoi Village, Agatsuma County 03:13:10 Sedo no Taki (Waterfall) - Mihara, Tsumagoi Village, Agatsuma County 03:19:43 Route 144 overlap ends / Route 145 overlap section / Route 146 intersection / Monument of the three starting points of the national highway - Haneo, Naganohara-machi, Agatsuma County 03:21:24 Route 292 intersection / Route 145 overlap ends - Ōtsu, Naganohara-machi, Agatsuma County 03:27:38 Naganohara Megane Bridge (Agatsuma River) - Naganohara, Naganohara-machi, Agatsuma County 03:28:33 Route 145 overlap ends - Yokokabe, Naganohara-machi, Agatsuma County 03:33:44 Fukasawa Bridge - Yokokabe, Naganohara-machi, Agatsuma County 03:39:11 Sugao Pass - Sugao, Higashi-Agatsuma-machi, Agatsuma County 03:39:40 Nurukawa Bridge (Nuru River) - Motojuku, Higashi Agatsuma-machi, Agatsuma County 03:57:22 Ōdo Post Office - Ōdo, Higashi-Agatsuma-machi, Agatsuma County 04:05:14 Gonda, Kurabuchi-machi, Takasaki City 04:05:45 Kurabuchi Onsen Chōju no Yu, *Weakly alkaline low temperature spring - Gonda, Kurabuchi-machi, Takasaki City 04:13:47 Roadside Station Kurabuchi Oguri no Sato - San'nokura, Kurabuchi-machi, Takasaki City 04:20:22 Harunagawa Bridge (Haruna River) - Kamimuroda-machi, Takasaki City 04:28:31 Muroda Intersection - Kamimuroda-machi, Takasaki City 04:31:32 Satomi Post Office - Kamisatomi-machi, Takasaki City 04:47:11 Route 406 end point (Kimigayo Bridge West intersection = Route 18 intersection) - Shimotoyooka-machi, Takasaki City