Jan 03, 2021 (Nikkei) - The idea of a tunnel for auto traffic between Japan's main island of Honshu with Hokkaido to the north has gained new momentum after years of being considered a wasteful long shot.
The 31-km undersea tunnel would cost 720 billion yen ($6.97 billion) and serve as a complement to the existing, rail-only Seikan Tunnel, according to a proposal submitted last month to Transport Minister Kazuyoshi Akaba.
The massive undertaking would test the engineering ability of the country that produced the Seikan Tunnel, one of the world's longest and deepest tunnels. It would face the same budget constraints and labor shortages that have hampered other big Japanese infrastructure projects in recent years.
But proponents say the project makes economic sense as a means of cutting transport costs and boosting the movement of people and goods.
"This is a well-conceived proposal," said Yoshiharu Ishii, a visiting professor at the Hokkaido University Public Policy School.
Hokkaido is the only one of Japan's big islands that is not linked to Honshu by a bridge. Cars and trucks cannot drive through the Seikan Tunnel, which is only for bullet and freight trains.
The idea of a second tunnel under the Tsugaru Strait emerged in the middle of the last decade. It evolved into a plan for a two-deck construction, with the top level for self-driving vehicles and the bottom level for freight trains. Vehicles not equipped for autonomous driving would ride on flatbed trucks.
Last month's proposal by the Japan Project-Industry Council estimates the economic benefits of a second tunnel at 87.8 billion yen a year. Agricultural shipments from Hokkaido, one of Japan's biggest farming regions, would rise by 600,000 tons, generating 34 billion yen of economic value. The tourism from increased travel would yield 53.8 billion yen, according to the proposal.
Hokkaido's capital, Sapporo, is about 1,150 km from Tokyo -- about the same as the distance between Tokyo and the southwestern Japanese city of Fukuoka. Yet truck shipments cost 34% more on the northerly route, at 210,500 yen per 10 tons, according to a study by the Hokkaido Economic Federation.
The proposed tunnel would take about 15 years to build, from initial surveys to completion.
