Tokyo Bay Aqua-Line

The nihongo|Tokyo Bay Aqua-Line|東京湾アクアライン|tōkyō wan akua rain is a bridge-tunnel combination across Tokyo Bay in Japan. It connects the city of Kawasaki in Kanagawa Prefecture with the city of Kisarazu in Chiba Prefecture, and is designated as part of National Route 409. With an overall length of 14 km, it includes a 4.4 km bridge and 9.6 km tunnel underneath the bay—the longest underwater tunnel for cars in the world.

Overview

At the bridge-tunnel crossover point, there is an artificial island called nihongo|Umi-hotaru|海ほたる|Umi-hotaru, ("sea firefly") with a rest area consisting of restaurants, shops and amusement facilities. Air is supplied to the tunnel by a distinctive tower in the middle of the tunnel (called the "Kaze no tō" (風の塔)) which uses the bay's almost-constant winds as a power source.

The road opened on December 18, 1997 after 31 years of construction at a cost of 1.44 trillion yen (11.2 billion USD at the time of opening).

The Tokyo Bay Aqualine reduced the drive between Chiba and Kanagawa, two important industrial regions, to 15 minutes, and also contributed to cut time to go to sea leisure area in south Boso Peninsula from Tokyo and Kanagawa. Before the tunnel opened, one had to drive a roundabout 100km along the shores of Tokyo Bay and pass through the center of Tokyo.

One goal expressed during the planning of the Aqualine was to reduce the traffic through the center of Tokyo, but as the highway toll is quite high (3,000 yen cash for cars), the reduction in Tokyo traffic has not been as great as expected.

Using Tokyo Bay Aqua-line, many highway bus services are now provided, such as line from Tokyo Station to Kisarazu, Kimitsu, Kamogawa, Katsuura and Tateyama, and from Yokohama station or Haneda Airport to Kisarazu, Kimitsu and Tateyama, which cost much cheaper considering the highway toll of Aqualine.

Tolls and U-turns

As mentioned above, the current cash toll for a single trip on the Aqualine is 3,000 yen for ordinary-size cars; however, discounts, 2,320 yen, are available for drivers who utilize the ETC (electronic toll collection system). In general, tolls for usage of the Aqualine in either direction are collected at the mainline toll plaza on the Kisarazu end of the Aqualine.

One notable feature of the Umi-hotaru rest area is the fact that visitors to this complex can choose to either continue across Tokyo Bay or re-enter the highway in the opposite direction upon exiting the facility. In other words, it is possible to make a legal U-turn on the Aqualine by driving through the rest area's parking facility and then following signs to the appropriate onramp.

Users of the Aqualine will pay the applicable toll exactly once per trip, even those who elect to make a U-turn at the Umi-hotaru complex. Drivers who do choose to make the U-turn will either pay the full one-way Aqualine toll or pull a proof-of-payment ticket upon leaving the Umi-hotaru parking facility, depending on whether they arrived at Umi-hotaru from the Kawasaki side or the Kisarazu side.

See also

* List of bridge-tunnels‎
* Chesapeake Bay Bridge-Tunnel

External links

* [http://www.jhnet.go.jp/aqua-line/ Japan Highways site (in Japanese)]
* [http://www.driveplaza.com/etc/uturn.html NEXCO East's info regarding U-turns at Umi-hotaru (in Japanese)]