Then, in 2011, a rival claim from China threatened to oust the nearly 24-mile bridge from the top spot. But the causeway wasn’t bowing out without a fight.

When New Orleans expanded in the 1940s and 1950s, access to the north of the city became a problem. For people heading north from the city, or traveling south towards New Orleans, one major obstacle had to be circumvented: Lake Pontchartrain.

It was a time-consuming process to head east or west around the lake, so plans were made to create a direct connection across the center of the lake to its northern shore. In 1955, the Louisiana Bridge Company was created to undertake the construction project. It took just 14 months to build the first two-lane span of the causeway, which opened in 1956 with a total length of 23.86 miles.

It is such a long bridge that motorists lose sight of land for an eight-mile stretch, and drivers have been known to freeze out of some kind of false seaborne fear, at which point the police have escorted them off the bridge. Babies have been born on the causeway when their mothers failed to make it to the hospital on the other side. And an airplane once ran out of gas over the lake, eventually landing safely on the bridge.

A decade after the completion of the first bridge, daily traffic had surpassed 5,300 vehicles. 

Plans were made to expand the causeway by building a second two-lane span parallel to the original. The second bridge was opened in 1969, separated from the original by about 84 feet.

The second span was only about 50 feet longer than the original, but it was enough to finally catch the attention of the Guinness Book of World Records (first published in 1955). The Lake Pontchartrain Causeway was officially recognized as the longest bridge over water in the world, a record it held—unchallenged—until 2011.

Then in July 2011, Guinness announced that the newly completed Jiaozhou Bay Bridge in China was now the world’s longest bridge over water. With a total length of 26.5 miles, it was undoubtedly longer than the Lake Pontchartrain Causeway. People loyal to the causeway, however, were quick to point out that the criteria of measurement used by Guinness included aggregate structures, which would include land bridges at the ends of the main bridge and an undersea tunnel. In other words, elements that were distinctly not “over water.”

The controversy was soon put to bed when Guinness quite reasonably decided to create two new categories. Lake Pontchartrain Causeway became the “longest bridge over water (continuous),” while the Jiaozhou Bay Bridge became the “longest bridge over water (aggregate).” And while the Jiaozhou Bay Bridge has since lost its title to the Hong Kong-Zhuhai-Macau Bridge, which opened in October 2018, the Lake Pontchartrain Causeway remains the world’s longest bridge continuously over water, more than 60 years after the completion of its original span.