High Quality Content by WIKIPEDIA articles! U.S. Highway 90, one of the major east–west U.S. Highways in the Southern United States, runs through southern Louisiana for 304.8 miles (490.5 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.