US 90 (LA)
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.
The stretch between Lafayette and New Orleans is planned as a southern extension of Interstate 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 U. S. 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; US 90 was shifted to it from its former alignment (now Louisiana Highway 182) once it was completed.
US 90 replaced almost all of the Louisiana section of the San Diego–St. Augustine Old Spanish Trail. It was also designated Louisiana Highway 2 until the 1955 renumbering. A long section of the old road, from Lafayette to northeast of Raceland, is now Louisiana Highway 182.
U.S. Route 90 enters Louisiana at the Texas line over the Sabine River as part of Interstate 10 (I-10). Separating at exit 4 and running parallel on the north side of I-10 through Sulphur, before rejoining I-10 east of Westlake, crossing the Calcasieu River, and again splitting from I-10 at exit 31b (running on the south side of I- 10) going through Lake Charles as Fruge, West 4th, then East 4th, before leaving town. In Iowa U.S. 90 intersects with the southern terminus of U.S. Route 165 continuing east through Lacassine, Welsh, Roanoke, Jennings, and Mermentau.East of Mermentau U.S. 90 runs north of and parallel to a section of the Old Spanish Trail through Midland, Estherwood, and Crowley. In Crowley U.S. 90 makes a north then east jog, bringing it close and parallel to I-10, passing through Rayne, Duson, Scott, and then into Lafayette.
From Lafayette, U.S. 90 traverses a south by southwest course to Patterson, where the highway takes a more easterly direction to New Orleans. The section east (south) of Broussard, beginning east of Captain Cade road but west of Louisiana highway 88, to just west of Patterson, has been improved to interstate grade and completed in June 2011. These improvements include the completion of the overpasses at Coteau road (Louisiana Highway 88), Jefferson Island road (Louisiana highway 675), Center street (LA 14), Avery Island road (Louisiana highway 329), South Lewis street (Parish road 605), weeks Island road (Louisiana highway 83), Darnall road (Parish road 211), Patout road (Louisiana highway 85), and Canal street (Louisiana highway 671). This section ties into the already completed section that begins at Louisiana highway 318 and terminates at East Main street (Louisiana highway 182) just east of Calumet. West of Berwick U.S. 90 is listed as "interstate grade" with a 70 miles (110 km) per hour speed limit from (mile marker 174) to east of Raceland and an intersection with LA 1 (mile marker 215b), before reverting back to a standard divided highway and continuing on a north/northeast direction to New Orleans.
U.S. 90 enters Jefferson Parish and, after passing Avondale, heads north at an intersection with the U.S. Highway 90 Business called the Westbank Expressway, through Bridge City, and across the Mississippi River over the Huey P. Long Bridge. Crossing the river U.S. 90, designated as S. Clearview Parkway, intersects with and runs east as the Jefferson Highway, that was originally part of the "Interstate Trail" and the "Pine to Palm" highway, a 2,300 miles (3,700 km) mile north/south transcontinental U.S interstate highway running from New Orleans to the United States—Canadian border, then to Winnipeg, Canada The highway terminus was at the corner of St. Charles avenue and Common street with a monument that was erected in 1916. The original highway was changed to follow U.S. 90 and Louisiana highway 48. After 1935 Jefferson became S. Claiborne Avenue at the Orleans Parish line and makes a sweeping south to north semi-circle weaving through New Orleans. As the highway swings north it intersects and runs under an elevated I-10 becoming N. Claiborne for a short distance (two blocks), intersecting and running northwest as Canal Street, intersecting and running northeast as North Broad Avenue, intersecting and running northwest as St. Bernard Avenue, Paris Avenue north, then Gentilly Blvd. east becoming Chef Menteur highway.
East of New Orleans U.S. 90 crosses the Rigolets Bridge; it was near this crossing where Jayne Mansfield was killed.
U.S. 90 then enters Slidell. After exiting Slidell it heads east and crosses the Mississippi state line at a drawbridge at the Pearl River.
The Business U.S. 90 portion of the Pontchartrain Expressway is also designated as Interstate 910, however it is not signed as such. This is a temporary designation that overlaps all freeway portions of Business U.S. 90 (the Pontchartrain Expressway, Crescent City Connection, and Westbank Expressway). When Interstate 49 is completed from Lafayette to New Orleans, Business U.S. 90/Interstate 910 will be resigned as Interstate 49.
In Louisiana, current plans call for parts of U.S. 90 to be upgraded to interstate standards from Lafayette to just west of New Orleans and designated Interstate 49. The stretch of U.S. 90 to be upgraded to I-49 stretches from the West Bank Expressway (U.S. 90 Business near Westwego, Louisiana) to just north of downtown Lafayette, where U.S. 90 splits from U.S. Route 167 (the two highways converge in downtown Lafayette). The stretch of U.S. 167 from U.S. 90 to I-10 will also be upgraded and included as part of I-49. As of March 2008, due to a one billion dollar surplus in the Louisiana state budget, the legislature approved a bill which proposed capacity improvements on U.S. 90 in the Lafayette Area.[citation needed] U. S. 167/U.S. 90 is currently six-laned from I-10 to Pinhook Road. The plan[which?] calls for six-lanes from Pinhook to the suburb of Broussard. The lanes are expected to be opened in two years.[when?][citation needed]