U.S. Highway 11 (US 11) is a part of the United States Numbered Highway System that spans 1,756 miles (2,826 km)[lower-alpha 1] from New Orleans, Louisiana to Rouses Point, New York. Within the state of Louisiana, the highway travels 31 miles (50 km) from the national southern terminus at US 90 in New Orleans to the Mississippi state line south of Picayune.
From Eastern New Orleans, US 11 crosses Lake Pontchartrain on the nearly five-mile-long (8.0 km)Robert S. Maestri Bridge. The route parallels Interstate 10 (I-10) into Slidell, serving as that city’s major north–south arterial. After crossing I-12, US 11 parallels I-59 to the town of Pearl River, at which point the two highways proceed concurrently across the state line.
The portion of US 11 between Slidell and Pearl River was once part of the Old Spanish Trail, an early auto trail that largely became the route of US 90 when the U.S. Highway System was implemented in 1926. US 11 originally terminated in Mississippi just northwest of what is now the John C. Stennis Space Center. In 1937, US 90 was relocated onto a new route bypassing Slidell and Pearl River, significantly reducing the distance between New Orleans and the Mississippi Gulf Coast. US 11 was extended into Louisiana two years later over the former alignment of US 90, and the two routes were co-signed into Downtown New Orleans. This concurrency was discontinued in 1951 with US 11 being cut back to its current southern terminus at US 90 in Eastern New Orleans.
Until the construction of the Interstate Highway System in the area during the late 1950s to mid-1960s, US 11 was one of two major routes eastward out of New Orleans, the other being US 90. Both still serve as important alternate routes to I-10 when hurricanes threaten the area, as was perhaps most evident when, in August 2005, Hurricane Katrina heavily damaged the nearby I-10 Twin Span Bridge over Lake Pontchartrain, rendering the crossing completely impassable for over six weeks. (The Maestri Bridge on US 11, constructed in 1928, had sustained only minor damage.) North of Pearl River, US 11 does not serve a similar function, however, since it was moved onto I-59 in 1965 and no longer retains a separate crossing over the various branches of the Pearl River system.
From the south, US 11 begins at an intersection with US 90 (Chef Menteur Highway) in Eastern New Orleans between Michoud and Venetian Isles. It heads north along Ridgeway Boulevard as an undivided two-lane highway and travels through an area of marshland known as Irish Bayou. After 5.5 miles (8.9 km), the highway reaches Point Aux Herbes, where it passes through an interchange with I-10 at exit 254. US 11 immediately continues northeast onto the Robert S. Maestri Bridge, a 4.8-mile-long (7.7 km) span across Lake Pontchartrain that parallels the I-10 Twin Span Bridge.
About midway across the lake, US 11 crosses from Orleans Parish (coextensive with the city of New Orleans) into St. Tammany Parish and begins to closely follow the east side of the Norfolk Southern Railway (NSRW) trestle. Making landfall in North Shore, US 11 becomes known as Pontchartrain Drive and passes through the community of Eden Isle. At Oak Harbor Boulevard, the highway enters the city of Slidell and widens to accommodate a center turn lane and a second travel lane in each direction. This portion of the highway serves as a commercial corridor for the surrounding suburban area.