Fun & Easy Science for Kids
Sponsored Links :

Tokyo Bay Aqua Line


The Trans-Tokyo Bay Highway in Japan is also known as the Tokyo Bay Aqua Line. It is a 15.1 km long marine crossing connecting Kawasaki, Kanagawa Prefecture, to Kisarazu, Chiba Prefecture. It is mainly made up of a bridge-tunnel combination across the Tokyo Bay, forming part of National Route 409.

The Aqua Line consists of a 9.5-km shield tunnel (the Tokyo Bay Tunnel) and a 4.4-km bridge from an artificial island to the Kisarazu landing. It is the fourth longest underwater tunnel in the world. It also has the largest diameter for an underwater shield tunnel which is used for motor vehicle traffic.


Quick Facts: –

  • The Tokyo Bay averages only about 40 feet (12 meters) in depth.
  • The bay is linked with the Pacific Ocean by the Uraga Channel.
  • In the middle of the tunnel, there is Kaze no To, the Tower of Wind. It supplies fresh air to the tunnel.
  • At the end of the tunnel, there is a small artificial island called  Its name translates as ‘Sea Firefly’.
  • In clear weather, the viewing platforms on the 4th and 5th floor of Umihotaru Rest House offer great views over the whole Tokyo waterfront.
  • The expressway opened on December 18, 1997, after 9 long years of construction at a cost of $11.2 billion at the time of opening.
  • When the Tokyo Bay Aqua Line was opened in 1997, the toll for a regular car was 4,000 yen.
  • In 2000, the toll fee was lowered to 3,000 yen. After two years, in 2002, it was again lowered to 2,320 yen ETC toll.



Cite This Page

You may cut-and-paste the below MLA and APA citation examples:

MLA Style Citation

Declan, Tobin. " Fun Facts for Kids about Tokyo Bay Aqua Line ." Easy Science for Kids, May 2020. Web. 26 May 2020. < >.

APA Style Citation

Tobin, Declan. (2020). Fun Facts for Kids about Tokyo Bay Aqua Line. Easy Science for Kids. Retrieved from

Cite this Page

Sponsored Links :