The Sakanashi Tunnel (坂梨トンネル ''Sakanashi Tonneru'') is a tunnel on the border of Akita Prefecture and Aomori Prefecture on the

Tōhoku Expressway The is a south-north national expressway, and the longest expressway in Japan at . Its southern terminus is in Kawaguchi, Saitama in the Greater Tokyo Area, at the Tokyo Gaikan Expressway and Kawaguchi Route near Araijuku Station, and its no ...

. The tunnel crosses Sakanashi Pass of the northern Ōu Mountain Range. Its northbound tunnel is the longest tunnel on the Tōhoku Expressway. Its completion in 1986 was one of the final pieces of the Tōhoku Expressway from

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

to Aomori.

Description

The northbound bore of the tunnel is long while the southbound bore is long. The northern end of the tunnel sits at above sea level and the southern end sits at . The speed limit in the tunnel is set at 70 km/h. The tunnel is the longest on the Tōhoku Expressway.

Alternate route

Prior to the opening of the tunnel the primary high-speed route from Morioka to Aomori was the

Michinoku Toll Road The Michinoku Toll Road (みちのく有料道路 ''Michinoku Yūryōdōro'') is a two-lane expressway, two-lane toll road in Aomori Prefecture connecting the cities Aomori, Aomori, Aomori and Hachinohe, Aomori, Hachinohe via Shichinohe, Aomori, Sh ...

. That route is currently being extended to relieve National Route 4 and the Tōhoku Expressway of traffic from Hachinohe to Aomori, via the

Hachinohe Expressway The is a 4-laned national expressway in the prefectures of Iwate and Aomori in the Tōhoku region of Japan. It is a spur of the Tōhoku Expressway, primarily serving the city of Hachinohe. Signed as E4A, it is owned and operated by East Ni ...

, Second Michinoku Toll Road, and Kamikita Expressway. National Route 282 runs parallel to the tunnel, but winds through the mountain pass.

History

The Sakanahi Tunnel opened on 30 July 1986. This allowed the expressway to open between

Kazuno, Akita is a cities of Japan, city located in Akita Prefecture, Japan. , the city had an estimated population of 28,329 in 12,570 households, and a population density of 40 persons per km2. The total area of the city is . Geography Kazuno is located in ...

and

Hirakawa, Aomori is a Cities of Japan, city located in Aomori Prefecture, Japan. , the city had an estimated population of 30,086 in 14,181 households, and a population density of 89 persons per km2. The total area of the city is . Geography Hirakawa is located ...

References

{{Authority control Road tunnels in Japan Tunnels completed in 1986 1986 establishments in Japan Tōhoku Expressway Roads in Akita Prefecture Roads in Aomori Prefecture Tunnels in Aomori Prefecture Transport buildings and structures in Akita Prefecture