On our travels, we cross long and tall ones. Bridges, especially road bridges, are part of the landscape that we consider common when we go along roads tens of metres above a river or a valley. In some cases, however, we are dealing with engineering work that, in terms of their size and technical aspects, leaves us speechless. Think of the Millau Viaduct in France, which boasts a height of 341 metres, or the Beipanjiang bridge in China, which stands 565 metres above the Beipan River.
Sometimes it is not the height of the bridge that amaze us, but rather their length. In Italy, for example, the record goes to the Coltano viaduct on the A12 motorway, which extends for 9.6 kilometres. In second place in our country, is the viaduct on the A19 motorway, which crosses the Fichera stream at a length of seven kilometres.
But the longest bridge in the world boasts even more noteworthy dimensions: in fact, it reaches an extension of 164,800 metres, more than the distance between Bari and Lecce in Italy.
Where is the longest bridge in the world? And how long are the other viaducts that stand out by extension?
Danyang-Kunshan Grand Bridge - With the aforementioned 164,800 metres in length, this viaduct wins the title for the longest bridge in the world. Its construction began in 2006 and, employing over 10,000 people, was completed in 2010 at a total cost of $8.5 billion. Such an incredibly long bridge was necessary to cross an area dotted with canals, rivers, lakes and rice fields. As part of the Beijing-Shanghai high-speed rail line, the longest bridge in the world is located between Shanghai and Nanjing in Jiangsu province. For nine kilometres, it passes over the waters of the Yangcheng lake.
Changhua-Koahsiung Viaduct - The second longest bridge in the world is located in Taiwan, and is about seven kilometres shorter than the Danyang-Kunshan Grand Bridge. The Changhua-Koahsiung viaduct is 157,317 metres long and is a key part of the Taiwan High -Speed Rail line. Completed in 2007, this bridge - given the particular geographical area between Baguazhang and Zuoying - was built following strict anti-seismic criteria.
Cangde Grand Bridge - Cangde Grand Bridge is third place at 115,900 metres. This bridge, like the Danyang-Kunshan Grand Bridge, is also located along the Beijing-Shanghai high-speed line. The viaduct has a total of 3,092 pillars and was completed in 2010, the same year as the largest bridge in the world.
Tianjin Grand Bridge - Even the fourth longest bridge in the world is located in Asia, again in China, and always on the railway network. Altogether 113,700 metres long, it extends between Langfang and Qingxian. Work began in 2006 and ended in 2010. The bridge was inaugurated in 2011.
Weinan Weihe Grand Bridge - We remain in China even for fifth place but this structure is detached from the extensions of the previously mentioned viaducts. The Weinan Weihe Grand Bridge is in fact 79,732 metres long. Its construction ended in 2008, so as to conquer - albeit briefly - the title of the longest bridge in the world. This viaduct is part of the Zhengzhou – Xi’an High-Speed Railway.
Hong Kong-Zhuhai-Macao Bridge - In sixth position there is a new entry, the Hong Kong-Zhuhai-Macao bridge, opened in 2018. This structure connects Hong Kong, Zhuhai and Macao - the most important cities of the delta of the Pearl River - crossing the Lingdingyang canal. Some 55,717 metres in length, the bridge was completed in 2017 after eight years of work. Some interesting data: the bridge was built using 400,000 tonnes of steel and has an underwater tunnel nearly seven kilometres long. The cost of the entire work, although unofficial, was about $7 billion. One last curiosity about this new entry: the shape of the bridge is reminiscent of the typical Chinese dragon.
Bang Na Expressway - Seventh place in the ranking is awarded to a bridge that is located in Thailand. It is 54 kilometres long, so slightly less than the Hong Kong-Zhuhai-Macao Bridge. Except for the crossing of a river, the railway viaduct rises over kilometres and kilometres of dry land. Designed in 1994 by Louis Berger, the bridge was completed in 2000. It was the longest bridge in the world until 2004.
Beijing Grand Bridge - To discover the eighth ranking, we return to the Beijing-Shanghai high-speed line. This railway viaduct, which extends for 48,153 metres, was completed in 2010 and inaugurated the following year.
Lake Pontchartrain Causeway - Here is the first and only bridge in the ranking located outside of Asia. The Lake Pontchartrain Causeway is in fact located in Louisiana, the United States, between the cities of Mandeville and Metairie. It crosses Lake Pontchartrain in its entirety. In reality, there are two bridges, one parallel to the other: the first was built in 1956, and is 38,400 metres long; the second, completed in 1969, is 15 metres longer, and is used for traffic to the south, in the direction of Metairie. Along the route to the north, the bridge is characterised by a pivoting section that allows the passage of large boats.
Wuhan Metro Bridge - With the 10th longest bridge in the world that closes this ranking, we return to China, and more specifically to the city of Wuhan. The Wuhan Metro Bridge with its 37,788 metres constitutes the entire Line 1 of the city subway, so as to win the title of the longest continuous viaduct in the world. Line 1 was built in 2004, making Wuhan the fifth Chinese city with a subway.