The Huey P. Long Bridge in Jefferson Parish, Louisiana, is a cantilevered steel through truss bridge that carries a two-track railroad line over the Mississippi River at mile 106.1 with two lanes of US 90 on each side of the central tracks.
Opened in December 1935 to replace the Walnut Street Ferry, the bridge was named for an extremely popular and notorious governor, Huey P. Long, who had just been assassinated on September 8 of that year. The bridge was the first Mississippi River span built in Louisiana and the 29th along the length of the river. It is a few miles upriver from the city of New Orleans. The East Bank entrance is at Elmwood, Louisiana and the West Bank at Bridge City. It was designed by Ralph Modjeski.
The widest clean span is 790 feet (240 m) long and sits 135 feet (41 m) above the water. There are three navigation channels below the bridge, the widest being 750 feet (230 m). The distinctive rail structure is 22,996 feet (7,009 m) long and extends as a rail viaduct well into the city. It has sometimes been described as the longest rail bridge in the US, but the nearby Norfolk Southern Lake Pontchartrain Bridge, at 5.8 miles (9.3 km), is considerably longer. The highway structure is 8,076 feet (2,462 m) long with extremely steep grades on both sides. Each roadway deck is a precarious 18 feet (5.5 m) wide, with two nine-foot lanes, but because of the railroad component, is unusually flat for a bridge of this height. Normally, bridges this high have a hump to accommodate the height but this bridge is flat to accommodate rail traffic.