Akashi-Kaikyo Bridge

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Akashi-Kaikyo Bridge (明石海峡大橋, Akashi Kaikyō Ō-hashi^?)

Carries	6 lanes of roadway
Crosses	Akashi Strait
Locale	Awaji Island and Kobe
Maintained by	Honshū-Shikoku Bridge Authority
Design	Suspension bridge
Longest span	1,991 metres (6,532 ft)
Total length	3,911 metres (12,831 ft)
Clearance below	65 meters
Opening date	April 5, 1998
Toll	2,300 Yen or US$20
Coordinates	34°36′59″N, 135°01′13″E

Coordinates: 34°36′59″N, 135°01′13″E

The Akashi-Kaikyo Bridge (明石海峡大橋, Akashi Kaikyō Ō-hashi^?), also known as Pearl Bridge, is a suspension bridge in Japan that crosses the Akashi Strait; it links Maiko in Kobe and Iwaya on Awaji Island as part of the Honshū-Shikoku Highway. It is the longest suspension bridge in the world to date, as measured by the length of its center span 1,991 metres (6,532 ft), substantially longer than the second longest suspension bridge, the Danish Great Belt Bridge. Total length is 3,911 metres (12,831 ft). It was planned to be one of three Honshū-Shikoku connecting bridges, annexing two borders of the Inland Sea.

Before the Akashi-Kaikyo Bridge was built, ferries carried passengers across the Akashi Strait in Japan. This dangerous waterway often experiences severe storms, and in 1955, two ferries sank in the strait during a storm, killing 168 children. The ensuing shock and public outrage convinced the Japanese government to draw up plans for a suspension bridge to cross the strait. The original plan was for a mixed railway-road bridge but when the bridge was begun in April 1986 it was restricted to road only, with six lanes. Actual construction did not begin until May 1988, and the bridge was opened for traffic on April 5, 1998. The Akashi Strait is an international waterway and required a 1,500 metres (4,921 ft) wide shipping lane.

The bridge has three spans. The central span is 1,991 metres (6,532 ft), with the two other sections each 960 metres (3,150 ft). The bridge is 3,911 metres (12,831 ft) long overall. The central span was originally only 1,990 metres (6,529 ft) but was stretched by a further metre in the Kobe earthquake on January 17, 1995.

It was designed on a two-hinged stiffening girder system, allowing it to withstand 286 kilometres per hour (178 mph) winds, earthquakes measuring up to 8.5 on the Richter scale, and harsh sea currents. The bridge also contains pendulums that operate at the resonant frequency of the bridge to dampen forces on it. The two main supporting towers are 298 metres (978 ft) above sea level.

The bridge can expand up to two meters in one day.

The total cost is estimated at ¥ 500 billion (≈USD 5 billion). This cost is expected to be defrayed by charging commuters a toll to cross the bridge. However, the toll is so high (2,300 Yen or 20US$) that, ironically, very few drivers actually use the expensive bridge, preferring instead to ride buses across the bridge or use the slower-but-cheaper ferries.

Two parks in proximity of the bridge have been built for tourists, one in Maiko (including a small museum) and one in Asagiri. Both are accessible by the coastal train line.