The Tokyo Wan Aqua-Line Expressway is a 15.1 km toll road crossing through the middle of Tokyo Bay connecting Kawasaki city in Kanagawa prefecture and Kisarazu city in Chiba prefecture.
Source: Ministry of Land, Infrastructure, Transport and Tourism website
As of Dec 2018
After approximately 20 years of surveys and 10 years of construction, the Tokyo Wan Aqua-Line Expressway opened to traffic on Dec. 18, 1997.
From design to execution, its construction represented a convergence of state-of-the-art technologies and know-how of the time. Many new technologies and construction methods were developed and implemented, and its construction was also referred to as the "Apollo project of civil engineering." Engineers had to overcome a vast variety of challenges, ranging from the soft soil of the sea floor to natural conditions such as wind, tide, and earthquakes, as well as marine traffic and environmental conservation in Tokyo Bay.
Undersea tunnel (Aqua Tunnel) construction
Bridge (Aqua Bridge) construction
The Tokyo Wan Aqua-Line Expressway consists of two-10km long tunnels (Aqua Tunnel) under Kawasaki waters and a 5 km long bridge(Aqua Bridge) over Chiba waters with two artificial island in between. Japan's first marine rest area "Umihotaru" is an artificial island constructed to shift the expressway from the tunnels to the bridge.
There is also a tunnel ventilation tower callded "Kazenotou (Tower of Wind)," on the artificial island in the mid-section of the undersea tunnel and a pyramid shaped Ukishima Ventilation Station near the tunnel entrance on the Kawasaki side.
The toll booth is located on the Kisarazu side.
Whereas users traveling from the Keihin area in Kanagawa to the Boso area in Chiba previously had to drive for nearly half the circumference of Tokyo Bay, travel times were considerably shortened after the Tokyo Wan Aqua-Line Expressway opened to traffic.
For example, the driving distance from Haneda Airport to the Kisarazu junction is approximately 60 km shorter in distance, and about 45 minutes shorter in driving time.
It also provides alternative routing options during disasters and other situations, enhancing the functions of the expressway network in the Tokyo Metropolitan Area.
＜Drive route from Kisarazu JCT to Haneda Airpor＞
The Tokyo Wan Aqua-Line Expressway plays a critical role in promoting inter-regional exchange between different regions of the Tokyo Metropolitan Area.
In order to deepen the knowledge of The Tokyo Wan Aqua- Line Expressway by more people, we offer tours that guide safety measures such as evacuation facilities in undersea tunnels that are not open to the general public.
The Tokyo Wan Aqua-Line Expressway is now open to the public as part of the efforts of the NEXCO EAST and the Trans-Tokyo Bay Highway Corporation in observing the "Opening attractive public facilities and infrastructure" policy being promoted in accordance with the national government's "Tourism Vision to Support the Future of Japan"