The three-way highway starts in Tongjiang City, Heilongjiang Province, and ends in Sanya City, Hainan Province, with a total length of 5,700 kilometers. It is the longest of the "five vertical and seven horizontal" main line planned by the state and is the only highway that runs through the coastal areas of China. China's north and south highway artery "[same three roads]" zero starting point on the card "road starts here, Jiang Hui here, Hai Tong here".