The Hokkaidō Shinkansen (北海道新幹線?) is a high-speed rail line currently under construction between Aomori (Honshu) and Hokkaido through the Seikan Tunnel. Construction started in May 2005, and the initial Shin-Aomori to Shin-Hakodate section is projected to open in 2015. On June 30th, 2012, the government approved construction of the line to Sapporo by fiscal 2035. The line will be operated by the Hokkaido Railway Company (JR Hokkaido).
Tōhoku and Hokkaido Shinkansen services are hoped to be operated at speeds of up to 360 km/h. The proposed journey time from Tokyo to Sapporo is advertised locally as 3 hours, 57 minutes.
At the present time the Seikan Tunnel can only carry narrow-gauge (1,067 mm) traffic (Kaikyō Line), but it will be upgraded to dual gauge, with both standard and narrow-gauge tracks.
In the early 1970s, two other Shinkansen routes were proposed for Hokkaido: Sapporo - Asahikawa (Hokkaido Shinkansen extension) and Oshamambe - Muroran – Sapporo (Hokkaido South Route). There were also further, unofficial plans to connect to Abashiri, Kushiro and Wakkanai. These plans have been indefinitely shelved.