||Japan: Plan to Put Tokyo Expressways Underground an Option, but an Extremely Costly One
||Monday, October 08, 2012
||Oct 09, 2012
The government is considering removal of aging sections of elevated lanes of the Metropolitan Expressways in Tokyo and burying the roads underground.
The greatest hurdle to this idea, which is the baby of the infrastructure ministry, is the huge construction cost, estimated at 4.3 trillion yen, which is close to the 5.4 trillion yen needed for the planned Chuo linear motor train line between Tokyo and Nagoya.
The first elevated lane of the expressway opened between the Kyobashi and Shibaura districts in 1962, two years before the Tokyo Olympics.
The Metropolitan Expressways are now 301 kilometers long, with about 90 kilometers constructed more than 40 years ago. About 1 million vehicles use the expressways every day.
To avoid trouble over purchasing land, many sections of the expressways were built over existing roads and rivers. About 80 percent of the lanes are elevated.
Although the expressways were built for speed and to avoid traffic jams, many sections of the Inner Circular Route, which runs around central Tokyo, are narrow and the maximum speed is limited to 50 kph, although 100,000 vehicles use the ring road daily.
Some people say this route, a section of which crosses Nihombashi Bridge, will be unnecessary after the completion of extensions on such highways as the Central Circular Route. Others voiced concern that if the old ring road was closed traffic jams would worsen.
On Oct. 1, members of a council set up by the Land, Infrastructure, Transport and Tourism Ministry inspected conditions on the elevated sections of Route No. 6 in Sumida Ward, Tokyo.
Tiny cracks were discovered along the bottom of concrete structures and it is feared concrete chunks could fall if measures are not taken to prevent this.
However, an employee of Metropolitan Expressway Co. said: "This place is not that bad. There are sections in much worse shape."
As of the end of fiscal 2009, repair work was needed at 96,600 places on the expressways. The figure was more than double that five years before.
Because of old designs and narrow lanes, traffic jams are common, particularly at expressway junctions.
But because the traffic volume is so great, the government has not yet been able to come up with a fundamental solution.
In April, the ministry's experts panel discussed redevelopment of aged sections of the expressways and in September considered three options--removal, rebuilding on existing routes, and redevelopment with underground tunnels. The third option was considered the most desirable.
Financing such massive construction work was the main bugbear. "Government funds are limited," Land, Infrastructure, Transport and Tourism Minister Yuichiro Hata said.
The ministry has so far failed to come up with concrete time schedule and practical plans for securing the vast funds needed for redevelopment of the expressways.
As a result, the first option--removing aged sections--is under consideration. Some people suggest priority should be placed on removing sections that would enhance scenic beauty.
When the Shinagawa section of the Central Circular Route opens and the Tokyo Outer Ring Road is extended by the end of next fiscal year, they will serve as an alternative route to the Inner Circular Route.
In 2006, when Junichiro Koizumi was prime minister, a plan was considered to remove the elevated section over Nihombashi bridge and replace it with an underground tunnel.
The main reason for this is that the bridge in Chuo Ward is a landmark and the starting point for all major roads in the Edo period (1603-1867). The plan was eventually abandoned.
Akinori Nagamori, chief of the secretariat of Meikyo Nihombashi Hozonkai, an association comprising local store owners and residents to preserve the bridge's scenery, said, "The [elevated] road should be removed if it's impossible to build a road underground."
Compared with similar expressways overseas, the Inner Circular Route is an extremely short 15 kilometers.
London and Washington have ring roads more than 100 kilometers long, while Paris and Beijing have 30-kilometer-long ring roads.
Maximum speed limits on foreign ring roads are 100 kph or higher, and some of them have six to eight lanes.
A traffic expert said, "Once the Central Circular Route is fully opened, the Inner Circular Route will be unnecessary."
However, Hideo Nakamura, president of Tokyo City University, an expert of civil engineering, said: "Simply removing expressway sections could worsen traffic jams on other roads. Putting all sections underground is hardly cost-effective."
In addition to the experts panels' options, he proposed a fourth option: burying part of the expressways underground while utilizing existing routes.