The first section of the expressway was opened to traffic in 1986. The final section of the expressway (25 km between Hida-Kiyomi Interchange and Shirakawagō Interchange) was opened on July 5, 2008.[2] A major component of this section is the Hida Tunnel, the second longest road tunnel in Japan[4] after the Kan-Etsu Tunnel. A total of 1.22 trillion yen was spent on planning and construction of the expressway over 36 years.[5]
The expressway is 4 lanes from Ichinomiya Junction to Fukubegatake Parking Area, and 2 lanes on all other sections. Construction to expand the route to 4 lanes is currently underway on the section between Fukubegatake Parking Area and Shirotori Interchange.[6] The speed limit is 80 km/h on 4-laned sections and 70 km/h on 2-laned sections.[2]
Features
At 1,086 meters, Matsunoki Pass between Shōkawa Interchange and Hida-Kiyomi Interchange is the highest point in the national expressway network.[7] A parking area is planned to open at this point.
There are a total of 54 tunnels either completed or under construction. After the Hida Tunnel, the Hakamagoshi Tunnel (between Fukumitsu Interchange and Gokayama Interchange) is the longest. Trucks carrying hazardous materials are forbidden from using the tunnel and must use alternate routes.
This article contains a bulleted list or table of intersections which should be presented in a properly formatted junction table. Please consult this guideline for information on how to create one. Please improve this article if you can.(November 2021)