# Japan National Route 350

National Route 350 (国道350号, Kokudō Sanbyaku gojūgō) is a national highway of Japan that traverses the prefecture of Niigata in a southwest–northeast routing. It connects the city of Jōetsu in southern Niigata Prefecture to the prefecture's capital city, Niigata, to the north along the Sea of Japan coastline; however the highway mainly functions as the main highway on Sado Island. It has a total length of 51.9 kilometers (32.2 mi) on land, but a total length of 163.2 kilometers (101.4 mi) with the distance traveled by the Sado Steam Ship across the Sea of Japan factored in.

## Route description

National Route 350 mainly functions as the main highway on Sado Island; however, it is connected by roll-on/roll-off ferries that cross the Sea of Japan to its termini on Honshu at Jōetsu and Niigata. It has a total length of 51.9 kilometers (32.2 mi) on land, but a total length of 163.2 kilometers (101.4 mi) with the distance traveled by the Sado Steam Ship across the Sea of Japan factored in.

## History

The car ferry between Niigata and Ryōtsu commenced service in March 1967. The opening of this connection led to an increase of vehicular activity on the island. In response, officials on Sado Island sought assistance from the national government to improve the roads of the island; however, the law governing Japan's national highways only allowed for highways that were connected to core cities, special cities, and prefectural capitals to be designated as national highways. These officials petitioned the then-Secretary-General of the Liberal Democratic Party, Kakuei Tanaka, to give the island a national highway by finding a loophole in the law. The loophole was that if the highway began in Niigata (the prefecture's capital city) and ended in Jōetsu (a special city) it did not matter where the highway was routed between. National Route 350 was established by the Cabinet of Japan in 1975 between the cities of Niigata and Jōetsu via the Sado Island ferry ports at Ryōtsu and Ogi, giving the island its only national highway.

## Major junctions

The route lies entirely within Niigata Prefecture.
| Location | km | mi | Destinations | Notes |
| Niigata | 0.0 | 0.0 | National Route 7 ends / National Route 8 ends / National Route 17 ends / National Route 113 ends / National Route 116 south / National Route 289 east / National Route 402 south | Northern terminus, highway continues south as National Route 116, northern end of concurrency with National Routes 7, 8, 17, and 113 |
| Niigata | 0.9 | 0.56 | National Route 7 north / National Route 8 south / National Route 17 south – Niigata Station | Southern end of concurrency with National Routes 7, 8, and 17 |
| Niigata | 1.3 | 0.81 | National Route 113 east – to Nihonkai-Tōhoku Expressway, Niigata Airport | Southern end of concurrency with National Route 113 |
| Sea of Japan | 3.0– 67.6 | 1.9– 42.0 | Sado Steam Ship (Niigata–Sado Ferry) | Sado Steam Ship (Niigata–Sado Ferry) |
| Sado | 67.6 | 42.0 | Niigata Prefecture Route 45 / Niigata Prefecture Route 65 south – Suizu, Mano | Northern end of concurrency with Niigata Prefecture Route 45 |
| Sado | 68.4 | 42.5 | Niigata Prefecture Route 45 / 81 north – Futatsugame, Washizaki | Southern end of concurrency with Niigata Prefecture Route 45, northern end of concurrency with Niigata Prefecture Route 81 |
| Sado | 71.8 | 44.6 | Niigata Prefecture Route 282 south – Sado Airport | |
| Sado | 72.5 | 45.0 | Niigata Prefecture Route 81 south – Niibo, Tokinomori Park | Southern end of concurrency with Niigata Prefecture Route 81 |
| Sado | 78.2 | 48.6 | Niigata Prefecture Route 306 west – Aikawa, Kubota | |
| Sado | 78.7 | 48.9 | Niigata Prefecture Route 181 – Ryōtsu Port, Niibo, Nakaoki | |
| Sado | 79.9 | 49.6 | Niigata Prefecture Route 381 south – Niibo, Hatano | |
| Sado | 81.1 | 50.4 | Niigata Prefecture Route 194 south – Kanamaru | |
| Sado | 84.4 | 52.4 | Niigata Prefecture Route 305 north – Nagaki | |
| Sado | 86.2 | 53.6 | Niigata Prefecture Route 45 north – Aikawa | |
| Sado | 90.6 | 56.3 | Niigata Prefecture Route 194 north – Chigusa, Kanamaru | |
| Sado | 92.7 | 57.6 | Niigata Prefecture Route 65 north – Ryōtsu Port, Hatano | Northern end of Niigata Prefecture Route 65 concurrency |
| Sado | 93.2 | 57.9 | Niigata Prefecture Route 65 south – Akadomari, Mano Goryo | Southern end of Niigata Prefecture Route 65 concurrency |
| Sado | 103.3 | 64.2 | Niigata Prefecture Route 432 east – Shizudaira, Sasagawa | |
| Sado | 107.0 | 66.5 | Niigata Prefecture Route 456 east – Shimokawamo, Osaki | |
| Sado | 108.6 | 67.5 | Niigata Prefecture Route 287 east – Hamochi Port, Hamochihongo | |
| Sado | 113.1 | 70.3 | Niigata Prefecture Route 543 west – Sawasakibana, Kanedashinden | |
| Sado | 115.0 | 71.5 | Niigata Prefecture Route 45 – Akadomari, Hamochi Port, Central Ogi | |
| Sea of Japan | 115.7– 161.2 | 71.9– 100.2 | Sado Steam Ship (Sado–Jōetsu Ferry) | Sado Steam Ship (Sado–Jōetsu Ferry) |
| Jōetsu | 161.2 | 100.2 | Niigata Prefecture Route 468 – Kakizaki, Ōgata | |
| Jōetsu | 161.6 | 100.4 | Niigata Prefecture Route 216 – Kubiki, Naoetsu Station | |
| Jōetsu | 162.3 | 100.8 | Niigata Prefecture Route 288 – to National Route 253, Tōkamachi, Uragawara, Naoetsu Station | |
| Jōetsu | 163.2 | 101.4 | National Route 8 – Nagaoka, Kashiwazaki, Toyama, Itoigawa   National Route 18 south – Jōetsumyōkō Station, Nagano, Myōkō | Southern terminus |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Route transition |||||