At 24 miles long, the Lake Pontchartrain Causeway in Louisiana is the world longest continuous over-water highway bridge.
The Causeway is one of the oldest prestressed concrete bridges in the United States. The Causeway consists of two parallel bridges that are supported by more than 9,500 hollow pilings 55 inches in diameter. Since its opening in 1956, traffic has grown from 3,000 vehicles per day to over 42.000 vehicles each week day From 1969 until 2011 it was listed in as the longest over-water bridge in the Guinness World Records.
In 2011 in response to the building of the Jiaozhou Bay Bridge in China Guinness created two categories of over-water bridges. The Causeway became the longest continuous over-water bridge, and the Jiaozhou Bay Bridge became the longest aggregate over-water bridge.
Additional information on the Lake Pontchartrain Causeway.