US 90 highlighted in red | ||||
Route information | ||||
Maintained by Louisiana DOTD | ||||
Length | 297.6 mi.[1] (478.9 km) | |||
Existed | 1926–present | |||
Major junctions | ||||
West end | ![]() ![]() | |||
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East end | ![]() | |||
Location | ||||
Country | United States | |||
State | Louisiana | |||
Parishes | Calcasieu, Jefferson Davis, Acadia, Lafayette, St. Martin, Iberia, St. Mary, Assumption, Terrebonne, Lafourche, St. Charles, Jefferson, Orleans, St. Tammany | |||
Highway system | ||||
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U.S. Highway 90 (US 90), one of the major east–west U.S. Highways in the Southern United States, runs through southern Louisiana for 297.6 miles (478.9 km), serving Lake Charles, Lafayette, New Iberia, Morgan City, and New Orleans. Much of it west of Lafayette and east of New Orleans has been supplanted by Interstate 10 (I-10) for all but local traffic, but the section between Lafayette and New Orleans runs a good deal south of I-10.
The stretch between Lafayette and New Orleans is planned as a southern extension of I-49 and is signed as "future corridor I-49". This part of the highway is important to the offshore petroleum industry, as it connects the cities of Lafayette and New Orleans to the port cities along the coast. Most of US 90 from New Iberia to New Orleans that has not already been improved to Interstate grade, is mainly an expressway, excepting the towns traversed through, that can be easily upgraded to freeway standards. The freeway east of Morgan City, bypassing Houma to the north, was originally built as Louisiana Highway 3052 (LS 3052); US 90 was shifted to it from its former alignment (now LA 182) once it was completed.
US 90 replaced almost all of the Louisiana section of the San Diego–St. Augustine running Old Spanish Trail. It was also designated Louisiana Highway 2 (LA 2) until the 1955 renumbering. A long section of the old road, from Lafayette to northeast of Raceland, is now LA 182.