is a major highway on the island of Honshū in Japan. It connects Chūō, Tokyo in the Kantō region with the city of Osaka, Osaka Prefecture in the Kansai region, passing through the Chūbu region en route. It follows the old Tōkaidō westward from Tokyo to Kyoto, and the old Kyo Kaidō from there to Osaka. Between Tokyo and Aichi Prefecture it parallels the Tomei Expressway; from there to Mie Prefecture, the Higashi-Meihan Expressway, and from Shiga Prefecture to Osaka, the Meishin Expressway. It has a total length of . At its eastern terminus in Nihonbashi, Chūō, Tokyo, it meets National Routes 4, 6, 14, 15, 17, and 20. At its western terminus in Umeda, Kita-ku, Osaka, it links with Routes 2, 25, 26 and other highways.
