It runs 15.91 miles (25.60 km) in a general southeast to northwest direction from the Mississippi River levee in Chalmette to the intersection of Hayne Boulevard and Downman Road in New Orleans.

LA 47 makes the shape of the number "7" and begins as a north–south route that travels along Paris Road through Chalmette, an unincorporated suburb of New Orleans and the seat of neighboring St. Bernard Parish.

Heading toward the back of town, LA 47 passes the Park Plaza Shopping Center (the location of the local post office) as well as Nunez Community College.

Upon exiting Chalmette, the center lane gives way to a median, and the highway continues into the marshland atop a narrow strip of dry land lined with small marine-related industries.

The first is exit 2C, a stingray-shaped diamond interchange that connects with Old Gentilly Road via Almonaster Boulevard and serves the nearby NASA Michoud Assembly Facility.

Continuing north, a more traditional diamond interchange at exit 1B serves Lake Forest Boulevard, and soon afterward, the abandoned Six Flags New Orleans theme park appears on the east side of the highway.

Just west of Crowder Boulevard, a ramp provides access to the New Orleans Lakefront Airport and the Senator Ted Hickey Bridge across the Industrial Canal.

LA 47 continues along Hayne Boulevard for another 1.3 miles (2.1 km) to an intersection with Downman Road, which parallels the industrial corridor located along the east side of the canal.

The southernmost portion of the route followed the existing Paris Road, originally platted in the early 19th Century as the main street of Versailles, an ambitious town plan that evolved into the present community of Chalmette.

[12][13][14] The route originally contained a swing bridge across Bayou Bienvenue on the St. Bernard–Orleans parish line, the remains of which can still be seen immediately to the west of the present fixed span.

[15][16] Shortly afterward, a gravel extension was completed north to Hayne Boulevard, giving St. Bernard Parish residents direct access to Little Woods, an area on Lake Pontchartrain lined with recreational camps built over the water.

Designed by the Army Corps of Engineers, the cantilever truss bridge with tied arch-suspended span contained four vehicular lanes and allowed all marine traffic to pass underneath unimpeded.

This involved the construction of a new roadway embankment through the swamp running parallel to the existing two-lane highway as well as a new fixed span bridge across Bayou Bienvenue.

The completed interstate spur was officially dedicated and opened to traffic by Louisiana Governor Edwin Edwards on November 13, 1992 after seven years of construction and an expenditure of $82 million.

The reconstructed route facilitated the movement of traffic between Chalmette and New Orleans East and provided a vastly improved outlet for St. Bernard and Plaquemines Parish residents during hurricane evacuations.

[33] Under this plan of "right-sizing" the state highway system, the entire portion of LA 47 from I-10 to the intersection of Hayne Boulevard and Downman Road is to be transferred back to the city of New Orleans as it does not meet a significant interurban travel function.