US 31E begins as the Ellington Parkway at the corner of Main Street and US 31, US 31W, US 41 and US 431 just east of Interstate 24. The freeway's interchanges in the middle of the route mainly includes locally maintained streets such as Cleveland Street, East Trinity Lane, Hart Lane, and Broadmoor Drive. Ellington Parkway ends at an interchange with SR 155, about east of the Briley's I-65 junction. A ramp directing Ellington Parkway's northbound traffic to I-65 north is provided at the Briley/Ellington junction. Access to Ellington Parkway southbound is also provided by a ramp from I-65 south via exit 90A. The road is named for former Tennessee governor Buford Ellington, who served two non-consecutive terms from 1959 to 1963, the other from 1967 to 1971. Ellington encouraged much road building throughout the state during his second term as governor. After Nashville, the highway passes through Hendersonville and Gallatin, Tennessee. It never intersects Interstate 40.
The American Association of State Highway Officials adopted a resolution against split routes in 1934. In order to eliminate the split in US 31 between Nashville, Tennessee, and Louisville, Kentucky, AASHO commissioned U.S. Route 37, replacing US 31E from the Louisville area south to Glasgow, Kentucky, where it then followed Kentucky Route 63 and several routes in Tennessee to Chattanooga. The rest of US 31E from Glasgow to Nashville was assigned U.S. Route 143. This proposed route was extended southwest to Centerville in 1938 and Jackson in 1944 via State Route 100 and State Route 20. US 31W would have become the main route of US 31. Kentucky and Tennessee refused to accept the renumbering and never changed signage for the routes. In 1952, AASHO re-recognized the split, officially restoring the US 31E and US 31W designations. US 31E once terminated at US 31 in Sellersburg, Indiana until 1980. It followed the current routing of US 31 from Sellersburg to Louisville.
Major intersections
Special routes
Hendersonville bypass route
An unsigned portion consisting primarily of Tennessee State Route 386 is known as the U.S. Route 31E Bypass.
U.S. Route 31E Business starts near the Southgate Shopping Center 0.379 mile north of the Exit 11 interchange of the Louie B. Nunn Cumberland Parkway, and intersects Kentucky Routes 249 and 63 before reaching the Barren County Courthouse at the Public Square. It then joins US 68 Business for only 0.123 miles before right-turning onto North Race Street. US 31E Business then follows North Race Street, passes the T.J. Samson Hospital, and ends at an intersection with the regular US 31E alignment on the north side of town about one mile south of the Veterans Outer Loop.
Major intersections
U.S. Route 31E Truck
U.S. Route 31E Truck is the truck route of US 31E in the Nelson County seat of Bardstown. The truck route consists of the following designations:
Kentucky Route 245 bypass from US 150 east of downtown to US 31E/150 north of downtown.
U.S. Route 31EX
U.S. Route 31EX is the business route of US 31E in the Bullitt County town of Mount Washington. The only two major intersections it has besides the main alignment is with KY 44 and KY 2706 in the town's business district. The route is long.