At 24 miles long, the Lake Pontchartrain Causeway in Louisiana is the world longest over-water highway bridge.

The Causeway is one of the oldest prestressed concrete bridges in the United States. To build the bridge, engineers loaded pieces of the bridge onto barges and transported them to the construction points on the lake. 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 3,500 vehicles during a peak hour.

Additional information on the Lake Pontchartrain Causeway