Tokyo Bay Aqua-Line


The Tokyo Bay Aqua-Line, also known as the Trans-Tokyo Bay Expressway, is an expressway that is mainly made up of 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 forms part of National Route 409. With an overall length of 23.7 km, it includes a 4.4 km bridge and 9.6 km tunnel underneath the bay—the fourth-longest underwater tunnel in the world.

Overview

At the bridge-tunnel crossover point, there is an artificial island called Umihotaru 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, which uses the bay's almost-constant winds as a power source.
The road opened on December 18, 1997, after 23 years of planning and 9 years of construction at a cost of 1.44 trillion yen.
The Tokyo Bay Aqua-Line reduced the drive between Chiba and Kanagawa, two important industrial regions, from 90 to 15 minutes, and also contributed to cutting the travel time to the sea leisure area in the southern part of the Bōsō Peninsula from Tokyo and Kanagawa. Before the tunnel opened, one had to drive around about 100 km along the shores of Tokyo Bay and pass through downtown Tokyo.
One goal expressed during the planning of the Aqua-Line was to reduce the traffic through downtown Tokyo, but as the highway toll is quite high, the reduction in Tokyo traffic has not been as great as expected.
Many highway bus services now use the Tokyo Bay Aqua-Line, including lines from Tokyo Station, Yokohama Station, Kawasaki Station, Shinagawa Station, Shibuya Station, Shinjuku Station and Haneda Airport to Kisarazu, Kimitsu, Nagaura station, Ichihara, Mobara, Tōgane, Kamogawa, Katsuura and Tateyama.

Tolls

The cash toll for a single trip on the Aqua-Line is ¥3000 for ordinary-size cars ; however, using the ETC system, the fare is ¥2320. The ETC toll is reduced to ¥1000 on Saturdays, Sundays and Holidays. In general, tolls for usage of the Aqua-Line in either direction are collected at the mainline toll plaza on the Kisarazu end.
Type of carTollETC Aqua-Line
Special discount		ETC Pilot Test discount
Normal cars3,000JPY2,320JPY800JPY
Midsize cars3,600JPY2,780JPY960JPY
Large cars4,950JPY3,830JPY1,320JPY
Specific large cars8,250JPY6,380JPY2,200JPY
Kei-cars and motorcycles2,400JPY1,860JPY640JPY