The is a national expressway in

Okayama Prefecture is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Okayama Prefecture has a population of 1,826,059 (1 February 2025) and has a geographic area of 7,114 Square kilometre, km2 (2,746 sq mi). Okayama Prefecture ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. It is owned and operated by

West Nippon Expressway Company The , abbreviated as , is one of the main operators of expressways and toll roads in Japan. It is headquartered on the 19th floor of Dojima Avanza in Kita-ku, Osaka. The company was established on October 1, 2005, as a result of the privatization ...

Naming

The expressway is officially referred to as the Chūgoku-Ōdan Expressway Okayama Yonago Route. The Chūgoku-Ōdan Expressway Okayama Yonago Route is the official designation for the Sanyō Expressway between Okayama Interchange and Okayama Junction, the Okayama Expressway between Okayama Junction and Hokubō Junction, the

Chūgoku Expressway The (part of Asian Highway Network ) is an expressway in Japan, which extends from Suita, Osaka to Shimonoseki, Yamaguchi. It connects Kansai and Chūgoku regions in western Honshu, Japan's main island. Other major cities along the express ...

between Hokubō Junction and Ochiai Junction, and the

Yonago Expressway The is a national expressway in the Chūgoku region of Japan. It is owned and operated by West Nippon Expressway Company. Overview The expressway is officially referred to as the Chūgoku-Ōdan Expressway Okayama Yonago Route. The route conne ...

between Ochiai Junction and Yonago Interchange (concurrent with the Chūgoku-Ōdan Expressway Okayama Yonago Route).

Overview

The first section of the expressway was opened in 1991. The final section of the expressway (41.2 km between Okayama-Sōja Interchange and Hokubō Junction) was opened on March 15, 1997. The route originates from its junction with the Sanyō Expressway and extends northward. At its northern terminus it connects to the Chūgoku Expressway. The expressway is 4 lanes from Okayama Junction to Kayō Interchange and the remainder is 2 lanes. The speed limit is 80 km/h on 4-laned sections and 70 km/h on 2-laned sections.

List of interchanges and features

* IC -

interchange Interchange may refer to: Transport * Interchange (road), a collection of ramps, exits, and entrances between two or more highways * Interchange (freight rail), the transfer of freight cars between railroad companies * Interchange station, a rai ...

, SIC -

smart interchange A is a feature of Japanese expressways that provides exclusive access to and from the expressway for vehicles equipped with electronic toll collection (ETC). The feature increases accessibility to and from the expressway in less-populated areas w ...

, JCT -

junction Junction may refer to: Arts and entertainment * ''Junction'' (2012 film), an American film * ''Junction'' (2024 film), an American film * ''Jjunction'', a 2002 Indian film * ''Junction'' (album), a 1976 album by Andrew Cyrille * Junction (E ...

, SA -

service area A rest area is a public facility located next to a large thoroughfare such as a motorway, expressway, or highway, at which drivers and passengers can rest, eat, or refuel without exiting onto secondary roads. Other names include motorway ser ...

, PA -

parking area A parking lot or car park (British English), also known as a car lot, is a cleared area intended for parking vehicles. The term usually refers to an area dedicated only for parking, with a durable or semi-durable surface. In most jurisdic ...

, BS -

bus stop A bus stop is a place where Public transport bus service, buses stop for passengers to get on and off the bus. The construction of bus stops tends to reflect the level of usage, where stops at busy locations may have shelter (building), shelters ...

, TN -

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

, BR -

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

External links

West Nippon Expressway Company
Expressways in Japan 1991 establishments in Japan {{Japan-road-stub