Longest Bridge In The USThe longest bridge in the United States is Lake Pontchartrain Causeway, it consists of two parallel bridges crossing Lake Pontchartrain in southern Louisiana, United States. The longer of the two bridges is either the fifth-longest or sixth-longest in the world depending on definitions, measuring at 23.87 miles (38.42 km) long. 

 
The bridges are supported by 9,500 concrete pilings. The two bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.Lake Pontchartrain Causeway In Summer 

 
Lake Pontchartrain Causeway

Lake Pontchartrain Causeway