The is a national expressway in the Chà «goku region of Japan. It is owned and operated by West Nippon Expressway Company.
The expressway is officially referred to as the Chà «goku-à Âdan Expressway Onomichi Matsue Route. The Chà «goku-à Âdan Expressway Onomichi Matsue Route is the official designation for the Sanyà  Expressway between Onomichi Interchange and Hiroshima Junction, the Onomichi Expressway between Onomichi Junction and Miyoshi-Higashi Junction, and the Matsue Expressway between Miyoshi-Higashi Junction and Matsue Interchange (concurrent with the Chà «goku-à Âdan Expressway Onomichi Matsue Route).
The first section of the expressway was opened in 2010. The final section of the expressway (18.4 km between Kisa Interchange and Sera Interchange) was opened on March 22, 2015. The route originates from its junction with the Sanyà  Expressway and extends northward. At its northern terminus it connects to the Chà «goku Expressway. The entire route is toll-free with the exception of the short (0.9 km) section between Onomichi Junction and Onomichi Toll Gate.
The route is 2 lanes for its entire length, with some overtaking areas. The speed limit is 70 km/h.