10 longest bridges in the US: From the Lake Pontchartrain Causeway to the Seven Mile Bridge

Published 22 June 2026 · us

America's longest bridges: 10 of the longest bridge crossings from Lake Pontchartrain Causeway to San Mateo-Hayward Bridge Rank Bridge Length 1 Lake Pontchartrain Causeway 23.83

America's longest bridges: 10 of the longest bridge crossings from Lake Pontchartrain Causeway to San Mateo-Hayward Bridge Rank Bridge Length 1 Lake Pontchartrain Causeway 23.83 miles (38.35 km) 2 Manchac Swamp Bridge 22.8 miles (36.7 km) 3 Louisiana Airborne Memorial Bridge (Atchafalaya Basin Bridge) 18.2 miles (29.29 km) 4 Chesapeake Bay Bridge-Tunnel 17.6 miles (28.32 km) 5 Bonnet Carré Spillway Bridge 11 miles (17.7 km) 6 Louisiana Highway 1 Bridge 8.26 miles (13.29 km) 7 Jubilee Parkway 7.5 miles (12.1 km) 8 San Mateo-Hayward Bridge 7 miles (11.27 km) 9 Seven Mile Bridge 6.79 miles (10.78 km) 10 General W.K. Wilson Jr. Bridge 6.08 miles (9.78 km) Longest bridges in the US ranked from Chesapeake Bay to Lake Pontchartrain Lake Pontchartrain Causeway Manchac Swamp Bridge Louisiana Airborne Memorial Bridge Chesapeake Bay Bridge-Tunnel PC: Official Website Bonnet Carré Spillway Bridge Louisiana Highway 1 Bridge PC: HNTB Jubilee Parkway San Mateo-Hayward Bridge Seven Mile Bridge General W.K. Wilson Jr. Bridge Most bridges are forgotten almost as soon as they are crossed. A few seconds over a river, a glance through the window, and the journey continues. The longest bridges in the United States belong to a different category altogether. These are structures that stretch for miles across open water, wetlands, and vast coastal landscapes, where the road seems detached from the surrounding land. In several cases, drivers spend so long on the bridge that the shoreline disappears from view entirely. Unsurprisingly, Louisiana dominates the rankings. The state's geography is a patchwork of bays, swamps, and marshes that leave engineers with little choice but to build roads above water. Together, these bridges tell a story not only about transportation but also about the landscapes that made them necessary.As reported by WorldAtlas, some of the longest bridges in the United States are far more than simple river crossings. Stretching across lakes, bays, swamps, and coastal wetlands, these vast structures carry motorists for miles over landscapes where traditional roads would be difficult, if not impossible, to build.Louisiana dominates the rankings thanks to its extensive network of marshes and waterways, with several of the country's longest bridges located within the state.

Check below the top 10 America’s longest bridges.Nothing else in the country quite matches the scale of the Lake Pontchartrain Causeway. Running nearly 24 miles across the broad waters of Lake Pontchartrain, it links the communities of Mandeville and Metairie on opposite sides of the lake.For much of the crossing, drivers are surrounded by water with little sense of how far they have travelled or how much remains ahead. The first span entered service during the 1950s, while a second parallel bridge arrived more than a decade later to accommodate growing traffic. The structure became internationally known through its long-standing record as the world's longest continuous bridge over water, a distinction it still retains in its specific category.A short distance behind the Causeway in length is the Manchac Swamp Bridge, another Louisiana giant. Carrying Interstate 55 across an immense swamp system, it extends for almost 23 miles through a landscape of cypress trees, waterways and marshland.The bridge forms a substantial section of the interstate itself. Travellers heading between New Orleans and Jackson often cross it without realising how much of the route is elevated above wetland. Local folklore has attached plenty of stories to the area over the years, giving the crossing a reputation that stretches beyond engineering and transport.The Louisiana Airborne Memorial Bridge is better known to most people as the Atchafalaya Basin Bridge. It cuts across the largest river swamp in the United States and forms a critical section of Interstate 10 between Baton Rouge and Lafayette.Driving across it offers a changing view of waterways, forests and floodplains. Rather than a single uninterrupted structure, parts of the crossing consist of parallel spans that come together at key points along the route. Since opening in the early 1970s, it has become one of the most heavily used long bridges in the country.Virginia's Chesapeake Bay Bridge-Tunnel occupies a category of its own.