The direct predecessors to National Route 58 in Okinawa are Military Road 1, which was established during the Battle of Okinawa and maintained by United States Civil Administration of the Ryukyu Islands, and Government Highway 1, which was maintained by the Government of the Ryukyu Islands until the islands were returned to Japan. The highway functioned as the island's main road during World War II and the subsequent US administration of the region. Military Road 1 was captured during the early stages of the Battle of Okinawa and it was quickly redeveloped by Japanese prisoners of war to facilitate the US effort to capture the island—and occupy it. The highway was mainly developed as a high-speed logistics route for the US military that could carry vehicles weighing up to 35 tons. It was re-designated as Government Highway 1 during the civil administration of the island, but the US military's vehicles still took priority over the local Okinawan driving community, who were not allowed to pass US military convoys and vehicles. After the return of the Ryukyu Islands from the United States to Japan on 15 May 1972, the aforementioned highways were all re-designated as a part of National Route 58. It remains the only Japanese national highway to be given a two-digit number following the reclassification of the Primary and Secondary National Highways as the General National Highways in 1965. Until 30 July 1978, traffic on National Route 58 in Okinawa Prefecture drove on the right rather than the left. After the 730 switch, Okinawa joined the rest of Japan in driving on the left in accordance to the Vienna Convention on Road Traffic.