is a national highway of Japan that traverses the prefecture of Niigata in a southwestâÂÂnortheast routing. It connects the city of Jà Âetsu 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 on land, but a total length of with the distance traveled by the Sado Steam Ship across the Sea of Japan factored in.
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 JÃ Âetsu and Niigata. It has a total length of on land, but a total length of with the distance traveled by the Sado Steam Ship across the Sea of Japan factored in.
The car ferry between Niigata and Ryà Âtsu 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 Jà Âetsu (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 Jà Âetsu via the Sado Island ferry ports at Ryà Âtsu and Ogi, giving the island its only national highway.
The route lies entirely within Niigata Prefecture.