Akashi Kaikyo Bridge is one of Japan’s most impressive engineering landmarks, connecting Kobe City on the main island of Honshu with Awaji Island in Hyogo Prefecture. Spanning the Akashi Strait, this enormous suspension bridge measures 3,911 meters in total length, with a central span of 1,991 meters. It forms part of the Kobe-Awaji-Naruto Expressway, one of the three major routes linking Honshu and Shikoku.
Known by the nickname “Pearl Bridge,” Akashi Kaikyo Bridge is admired for its elegant structure and spectacular nighttime illumination. Its immense scale, sweeping views of the sea, and striking appearance make it one of the most recognizable landmarks in the Kobe and Awaji Island area.
Akashi Kaikyo Bridge officially opened to traffic on April 5, 1998. The construction project cost approximately 500 billion yen and represented a major achievement in Japanese civil engineering.
The original design called for a total length of 3,910 meters and a central span of 1,990 meters. However, the Great Hanshin-Awaji Earthquake of January 1995 caused slight movements in the Earth’s crust, increasing the distance between the bridge’s anchorage points. As a result, the completed bridge became one meter longer than originally planned, reaching its final length of 3,911 meters.
When it opened, Akashi Kaikyo Bridge held the world record for the longest suspension bridge in the world, a distinction recognized by Guinness World Records. It retained that record until March 2022, when the 1915 Çanakkale Bridge opened across the Dardanelles Strait in western Turkey, with a central span of 2,023 meters.
Akashi Kaikyo Bridge is now the world’s second-longest suspension bridge by central span, but it remains a landmark of international engineering and a powerful symbol of Japan’s infrastructure capabilities.
The bridge is affectionately known as the Pearl Bridge, a name inspired by its graceful appearance and the beauty of its nighttime scenery. Its illuminated towers and cables create a striking silhouette against the dark sea and sky.
It is also sometimes called Akashi Ohashi, a shortened name used informally and on some expressway signs. However, this name can cause confusion with another bridge crossing the Akashi River in Akashi City, so Akashi Kaikyo Bridge is the clearest name when referring to this major suspension bridge.
Akashi Kaikyo Bridge uses a three-span, two-hinged stiffening-truss suspension design. This structure combines suspension cables with a stiffening truss to support the roadway and help the bridge withstand heavy traffic, strong winds, and other environmental forces.
Construction began in May 1988, and the bridge’s main structure was joined in September 1996. After the completion of the remaining work, the bridge opened to traffic in April 1998.
The two main towers rise approximately 298.3 meters above sea level. Their remarkable height makes them among Japan’s tallest bridge towers and a prominent feature of the surrounding coastal landscape.
The bridge’s stability depends on enormous anchorages that secure the main cables at either end. Because the geological conditions differ between the Kobe and Awaji Island sides, different construction methods were used for their foundations.
On the Kobe side, engineers used a diaphragm-wall construction method to create a foundation approximately 85 meters in diameter and 63.5 meters deep. On the Awaji Island side, a direct foundation method was adopted.
The two main towers support the bridge’s suspension cables. The distance between the tower tops is slightly greater than the central span measured at roadway level because of the Earth’s curvature and the geometry of the bridge structure.
The main cables are among the bridge’s most impressive engineering components. Two enormous cables support the suspended roadway, with each cable made up of 290 strands. Each strand contains 127 high-strength galvanized steel wires, resulting in a total of 36,830 individual wires across the two main cables.
The cables are designed to carry enormous loads, supporting the bridge’s weight and the traffic traveling across it. To protect the steel wires from moisture and corrosion, the cables are enclosed in protective coverings, and dehumidified air is continuously circulated inside them.
During construction, engineers also used a helicopter to carry out an aerial cable-installation operation across the strait, an innovative technique at the time. This helped demonstrate the advanced engineering methods required to build a bridge of such extraordinary scale.
The idea of building a bridge across the Akashi Strait dates back to before World War II. However, the technological challenges and military considerations of the time prevented the project from moving forward.
After the war, investigations into routes connecting Honshu and Shikoku gradually progressed. In 1955, Japanese National Railways began studying the proposed Honshu-Shikoku Bridge route, helping turn the long-standing concept into a more concrete infrastructure plan.
Several serious maritime accidents helped strengthen public support for safer transportation links between the islands. These included the sinking of the Sekirei Maru in 1945 and the Shiun Maru disaster in 1955.
The Shiun Maru disaster, in particular, intensified calls for a permanent connection between Honshu and Shikoku. These events contributed to the momentum behind the large-scale bridge projects that would eventually transform regional transportation.
The Honshu-Shikoku Bridge Authority was established in 1970 to advance the construction of bridges connecting the main island with Shikoku. Akashi Kaikyo Bridge became part of the Kobe-Naruto route.
The project was initially planned as a combined road and railway bridge, but the design was changed in 1985 to a road-only suspension bridge. The final structure was designed with a total length of 3,910 meters and a central span of 1,990 meters. Following the 1995 earthquake, the slight change in the distance between the anchorages resulted in the completed bridge measuring 3,911 meters.
Akashi Kaikyo Bridge is a vital transportation route connecting the Kansai region with Awaji Island and Shikoku. As part of the Kobe-Awaji-Naruto Expressway, it allows vehicles to cross the Akashi Strait directly, making travel between major cities in western Japan more convenient.
The bridge is an important component of the wider Honshu-Shikoku connection network, which consists of three principal routes. It supports regional mobility, tourism, and economic activity by linking communities that were once dependent on sea transport.
In 2014, a new expressway toll system was introduced as part of changes to the national expressway network. The bridge continues to operate as a major road infrastructure asset serving both local and long-distance traffic.
Beyond its practical role, Akashi Kaikyo Bridge is a popular sightseeing landmark. From the Kobe waterfront and nearby coastal parks, visitors can admire the enormous towers and cables stretching across the strait. The surrounding waters, passing ships, and distant shoreline create an ever-changing panorama.
The bridge is especially striking after sunset, when its illumination highlights the graceful lines of the suspension structure. Its nickname, Pearl Bridge, reflects the elegant appearance that makes it a favorite subject for photography.
Akashi Kaikyo Bridge represents the meeting of engineering innovation, regional history, and natural beauty. From its world-class dimensions to its role in connecting Honshu and Shikoku, it remains one of Japan’s most remarkable bridges and an unforgettable landmark for visitors to Kobe and Awaji Island.