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 northern terminus is at Aomori Interchange in Aomori, Aomori in the northern part of the Tōhoku region, where it meets the Aomori Expressway and Aomori Belt Highway near the Sannai-Maruyama Site.
It is owned by and operated by East Nippon Expressway Company. The expressway is signed E4 under the "2016 Proposal for Realization of Expressway Numbering", because it roughly parallels National Route 4.
Route description
The expressway links the Tōhoku region with the Kantō region and the greater Tokyo urban area. It is also the longest expressway among all expressways operated by East Nippon Expressway Company.
Starting at a junction with the Tokyo Gaikan Expressway to the north of Tokyo, the expressway follows a northerly course through the plains of Saitama Prefecture and Tochigi Prefecture before entering the mountainous interior of the Tōhoku region. Passing through central Fukushima Prefecture, the expressway then enters Miyagi Prefecture and passes to the west of Sendai, the largest city in the Tōhoku region. The expressway continues north into Iwate Prefecture, passing the prefectural capital Morioka. In the northern part of Iwate, the expressway veers to the northwest, while the Hachinohe Expressway branches off to the northeast. The Tōhoku Expressway continues into central Aomori Prefecture. Before terminating in the city of Aomori, the Aomori Expressway begins, continuing east as an extension of the expressway towards Hachinohe by a series of toll roads and expressways.
The route parallels the Tōhoku Shinkansen and Tōhoku Main Line of East Japan Railway Company as well as National Route 4 from its origin in Tokyo to the city of Morioka. North of Morioka, the route diverges to the northwest and parallels the Ōu Main Line and National Route 7. It follows this path winding through the Ōu Mountains to its northern terminus in Aomori at National Route 7 about a kilometer south of the Tōhoku Shinkansen's northern terminus at Shin-Aomori Station.
The expressway is 6 lanes from to Utsunomiya Interchange, and then changes to 4 lanes from Utsunomiya to the terminus in Aomori.
The standard rate for travelling the entirety of the Tōhoku Expressway in a normal-sized car from Kawaguchi Junction to Aomori Interchange is 13,800 yen, in a kei car the cost is 11,100 yen.
Naming
Tōhoku refers to the Tōhoku region, the northernmost region on the island of Honshū.
Officially the expressway is designated as the Tōhoku Jūkan Expressway Hirosaki Route. It is also concurrent with the Tōhoku Jūkan Expressway Hachinohe Route until , where it diverges from the Tōhoku Expressway to become the Hachinohe Expressway.