TOKYO (Kyodo) -- Construction work began Monday in Tokyo to relocate an elevated expressway running over the historic Nihombashi bridge underground in a 320 billion yen ($3 billion) project to be completed by around 2040.
Metropolitan Expressway Co. plans to construct a 1.1-kilometer underground tunnel in the area by 2035 while removing the overpass, built as part of the network to connect 1964 Tokyo Olympics venues with Haneda airport, by 2040.
In the initial phase of the construction work, an underground water line will be relocated along with other infrastructure before the tunnel is dug, according to the expressway operator.
The project covers a 1.8-km stretch of the expressway between the Kandabashi junction near Tokyo Station and Edobashi junction.
The stone bridge, constructed in 1911, is a designated national cultural property. The original Nihombashi bridge built in 1603 was the eastern terminus of the Tokaido, the ancient road people used to travel between Tokyo, then called Edo, and Kyoto.
Local residents had long protested that the expressway spoils the view of the 49-meter-long bridge, and a former land minister in 2001 had pledged to relocate the overpass in the Nihombashi area, an upscale shopping district.
The cost of the replacement work will be shouldered by the expressway operator, municipalities and companies planning redevelopment projects in Nihombashi.
A significant portion of the expressway in central Tokyo was laid over rivers and canals to minimize the need for land purchase negotiations and complete its construction in time for the Olympics.