U.S. Highway 90 Business (US 90 Bus.) is a business route of U.S. Highway 90 located in and near New Orleans, Louisiana. It runs in a general east–west direction from US 90 in Avondale to a junction with Interstate 10 (I-10) and US 90 in the New Orleans Central Business District.

Unlike a typical business route, US 90 Bus. is built to a higher standard than the segment of US 90 that it parallels. More than half of the route is an elevated freeway with frontage roads while mainline US 90 is a divided six-lane surface highway. It is also the only business route of a U.S. Highway in Louisiana that is not derived from a former alignment of its parent route. US 90 Bus. was newly constructed between 1954 and 1960 while the parallel section of US 90 has remained largely unchanged since 1936.

US 90 Bus. initially heads eastward along the Westbank Expressway, serving a number of suburban communities in Jefferson Parish located on the west bank of the Mississippi River. These include Westwego, Marrero, Harvey, and Gretna, the parish seat. After transitioning from a surface route to an elevated freeway in Marrero, US 90 Bus. traverses a high-level bridge over the Harvey Canal, a link in the Gulf Intracoastal Waterway, while the frontage roads pass through the Harvey Tunnel. Shortly after entering an area of New Orleans known as Algiers, US 90 Bus. curves due west onto the Crescent City Connection, a twin-span cantilever bridge across the Mississippi River. The highway continues alongside the downtown area as part of the elevated Pontchartrain Expressway to a complex interchange with I-10 and mainline US 90 adjacent to the Superdome.

The entirety of US 90 Bus. is intended to become part of I-49 once that highway is extended along the present US 90 corridor from Lafayette to New Orleans. In the meantime, the route carries the designation of Future I-49, as approved by the American Association of State Highway and Transportation Officials in 1999. While the Federal Highway Administration approved the existing freeway portion of US 90 Bus. to be signed as Interstate 910 in the interim, the Louisiana Department of Transportation and Development did not follow through with an application to the AASHTO's U.S. Route Numbering Committee, and the designation remains unused. This route exit 6A from the nearby west in Harvey in Gretna to New Orleans district.

Route description Westwego to Harvey Canal From the west, US 90 Bus. begins at a modified trumpet interchange with US 90 in a sparsely developed area of Jefferson Parish surrounded by the suburban city of Westwego, Bayou Segnette State Park, and an industrial area formerly known as Avondale Shipyard. Mainline US 90 connects with Boutte to the west and the Huey P. Long Bridge across the Mississippi River to the east (geographically north). Due to the proximity of the BNSF/Union Pacific Railroad overpass on eastbound US 90, the ramp from westbound US 90 Bus. travels in an indirect fashion and intersects an eastbound ramp at grade at a four-way stop. As a result, a significant amount of local traffic circumvents this movement by turning onto Nine Mile Point Road toward a signalized intersection with US 90 that features a protected no-stop turn lane.

US 90 Bus. heads southeast along the Westbank Expressway as a divided four-lane highway and intersects Segnette Boulevard, the entrance to the Alario Center and Bayou Segnette State Park. Soon afterward, US 90 Bus. widens to six lanes, and the median width increases from to . Upon entering the city of Westwego, US 90 Bus. becomes a developed commercial corridor, and an intersection with LA 18 Spur (Louisiana Street) provides a route for truck traffic to the industrial facilities along the riverfront. The highway crosses from Westwego into the unincorporated community of Marrero immediately past Victory Drive and curves due east, maintaining a parallel trajectory to the Mississippi River. At Carmadelle Street, several blocks past a signalized intersection with Westwood Drive, a ramp leads through traffic onto an elevated six-lane freeway, which begins in the median. The ground-level portion of the Westbank Expressway continues straight ahead as frontage roads serving local businesses and maintains a six-lane capacity.

After a short distance, the first in a series of tight diamond interchanges, exit 4A, connects with Ames Boulevard. As it is located near the west end of the freeway, the interchange consists only of an eastbound entrance and westbound exit with the remaining movements accessed from the frontage roads. The following exit (4B) connects with LA 45 (Barataria Boulevard) and leads to Jean Lafitte National Historical Park and Preserve as well as several communities situated alongside Bayou Barataria. This exit also serves the nearby West Jefferson Medical Center. US 90 Bus. proceeds through the neighboring unincorporated community of Harvey, which is bisected by the Harvey Canal, a link in the Gulf Intracoastal Waterway. An industrial corridor flanks the canal and stretches from the Mississippi River southward into Plaquemines Parish near Belle Chasse. A half-diamond interchange at exit 5 (MacArthur Avenue) serves the industrial area on the west bank of the canal. The highway elevates to a height of to cross the canal while the frontage roads pass underneath it via the Harvey Tunnel. Direct access to the facilities on the east side of the canal, situated along LA 3017 (Peters Road), is limited to a westbound exit ramp.

Harvey Canal to Mississippi River

East of the Harvey Canal, US 90 Bus. heads northwest, returning to its prior elevation and connecting to Manhattan Boulevard via exit 6. It then enters the city of Gretna, the seat of Jefferson Parish government. Two interchanges serve Gretna: exit 7 to LA 18/LA 23 (Lafayette Street) and exit 8 to Stumpf Boulevard. Between these two exits, the expressway frontage roads run concurrent with LA 23, which continues northwest onto Stumpf Boulevard. While passing alongside the Oakwood Center shopping mall, US 90 Bus. enters into its final interchange on the west bank: exit 9 to Terry Parkway and General de Gaulle Drive. These are parallel divided thoroughfares, the former serving the mall and adjacent neighborhood of Terrytown. The first portion of the exit is a tight half-diamond interchange consisting of an eastbound exit and westbound entrance that utilize the frontage roads to connect with both thoroughfares.

Immediately after crossing Terry Parkway, US 90 Bus. enters Orleans Parish and the city of New Orleans, which are co-extensive. All remaining movements on exit 9 are provided via a partial cloverleaf interchange at General de Gaulle Drive with flyover ramps connecting to Terry Parkway, and the US 90 Bus. frontage roads are discontinued at this point. General de Gaulle Drive is part of LA 428 and is the principal thoroughfare of Algiers, a name applied to the west bank section of New Orleans. The highway curves due west to begin its ascent onto the Crescent City Connection, a pair of cantilever bridges each carrying four lanes of through traffic across the Mississippi River. Additionally, the eastbound (geographically westbound) span contains two reversible HOV lanes, separated from the main travel lanes by a row of Jersey barriers. Due to the bend in the Mississippi River from which the "Crescent City" gets its name and the orientation of the bridges, the remainder of US 90 Bus. carries traffic signed "eastbound" and "westbound" in geographically opposite directions.

Downtown New Orleans

After climbing to a height of above the Mississippi River, US 90 Bus. enters the New Orleans Central Business District and crosses over the city's Convention Center. The highway simultaneously engages in an interchange with Tchoupitoulas Street at exit 11A, the designated exit for truck traffic associated with the Port of New Orleans. (This exit is signed westbound as exit 11 to Tchoupitoulas and South Peters Streets.) US 90 Bus. proceeds northwest onto the Pontchartrain Expressway, an elevated six-lane freeway in the center of Calliope Street, a divided surface street. Several overlapping interchanges with limited movements further serve the business district, beginning with exit 12A (Camp Street), which passes between the National World War II Museum and Lee Circle. This is followed by exit 12D (Carondelet Street/St. Charles Avenue). In addition to being a significant downtown street, St. Charles Avenue is a scenic oak tree-lined boulevard that traverses uptown neighborhoods such as the Garden District and Carrollton. Exit 12C connects with Loyola Avenue, a divided downtown thoroughfare that provides access to the Union Passenger Terminal and the city's two major entertainment venues—the Superdome and New Orleans Arena. At Loyola Avenue, Calliope Street becomes Earhart Boulevard, which serves as a frontage road for a short distance until US 90 Bus. departs from its alignment.

US 90 Bus. enters into a complex interchange with both US 90 (South Claiborne Avenue) and I-10. Separate ramps connect to westbound US 90 (exit 13A), eastbound US 90 (13B), and eastbound I-10 (13C). To the east, US 90 travels beneath the elevated I-10 as it passes through the downtown area en route to Slidell, located on the north shore of Lake Pontchartrain. Following exit 13C, eastbound US 90 Bus. continues straight ahead to merge with westbound I-10, which swings to the northwest to proceed along the Pontchartrain Expressway toward New Orleans International Airport and the city of Baton Rouge. Locally, westbound I-10 carries traffic between downtown New Orleans and the suburbs in Jefferson and St. Tammany parishes, the latter accessed via the Lake Pontchartrain Causeway.

Route classification and data US 90 Bus. is classified as an urban freeway by the Louisiana Department of Transportation and Development (La DOTD) and carries the internal designation of US 90-Z. Annual average daily traffic data collected by the department in 2019 showed a low of 38,818 vehicles near Westwego, increasing to a peak of 163,126 vehicles on the Mississippi River bridge. The remainder of the route through downtown New Orleans maintained at least 100,000 vehicles to the junction with I-10. The posted speed limit is along the surface portion of the route, increasing to throughout the west bank freeway portion. The remainder of the route across the Crescent City Connection and along the Pontchartrain Expressway is generally posted at .

The portion of US 90 Bus. between the Lafayette Street and Camp Street exits serves as a link in the ten-state National Scenic Byway known as the Great River Road.

History

The three main elements that constitute the route of US 90 Bus. in New Orleans—the Westbank Expressway, the Crescent City Connection, and the Pontchartrain Expressway—were initially conceived between the 1920s and 1940s as separate projects.

Early planning