I 310 (LA)
Highways in Louisiana
Interstate 310 (abbreviated I-310) is a short spur route of Interstate 10 near New Orleans, Louisiana, United States. It runs south from Interstate 10 near the New Orleans International Airport, intersects with U.S. Highway 61 and ends at the junction with U.S. Highway 90.
Interstate 310's mileage and exit numbers increase from north to south, the opposite of the standard Interstate numbering scheme.
Interstate 310's southern terminus is at US 90, where it travels north through flat marshlands. The southernmost mile was originally built as part of Louisiana Highway 3127, an inland bypass to Louisiana Highway 18, and is cosigned with I-310. North of I-310's first interchange, LA 3127 leaves the interstate, as I-310 heads towards the Mississippi River. After the next interchange, LA 18, Interstate 310 crosses the Mississippi River via the Luling Bridge (Hale Boggs Memorial Bridge), a cable-stayed bridge connecting the towns of Luling and Destrehan.
North of the bridge, there is an interchange with LA 48. I-310 then proceeds to the Destrehan Swamp Bridge, a five-mile (8 km) bridge over environmentally sensitive wetlands between Destrehan, Louisiana and the I-10 interchange. The northernmost two miles (3 km) of this bridge between the US 61 and I-10 interchanges was constructed using a method known as "end-on construction". This is a top-down technique in which construction platforms are mounted on concrete piles to avoid disrupting the environment below. From these platforms, the next set of piles and bridge viaducts are placed, allowing the platform to progress forward for the next set. The interstate terminates at I-10 just west of Kenner.
Interstate 310 was originally planned, along with Interstate 510, as part of Interstate 410, a southern beltway around the New Orleans metro area. In 1977, I-410 was cancelled and the two interstates were split into their current components. The Luling Bridge was completed in 1983, one of the first parts of I-310 to open. I-310 was built through the 1980s and early 1990s and was completed on May 7, 1993, with the last section of construction being the Destrehan Swamp Bridge.
Future plans for I-310 are to relocate the southern end of the interstate to connect with the future extension of Interstate 49 from Lafayette to New Orleans. Another proposal in the Louisiana Statewide Transportation Plan proposes an extension of the Earhart Expressway (Louisiana Highway 3139) westward from Dickory Avenue to Interstate 310 to serve as a freeway alternative I-10.[citation needed]
With discussions of extending I-510 across the Mississippi River, there is speculation of reviving the idea of a connection between I-310 and I-510.
Note: Exits numbers increase from north to south, the opposite of the standard Interstate numbering scheme.
The entire route is in St. Charles Parish.