The Japanese government has concurred with the Tokyo city authorities that a US$10.11bn 16km dual three-lane tunnel should be built as part of the 85km Gaikando expressway to complete Tokyo’s outer ring road. Transport minister Chikage Ogi said: “By also making the tunnel more compact, we can reduce costs by US$2.53bn.” Construction of the tunnel, which will comprise of two 18m diameter bores, will also slash the time taken to build the tunnel by half to just seven and a half years. The tunnel replaces an earlier proposal to build a viaduct, which has been opposed by local residents after it was put forward more than 30 years ago. More than 3,000 homes would have been demolished to make way for the viaduct whereas the road tunnel will affect 480 homes, according to the Ministry of Land, Infrastructure and Transport.
