US 31E begins as the Ellington Parkway at the corner of Main Street and US 31, US 31W, US 41 and US 431 (Spring Street) just east of Interstate 24 (I-24). It never intersects Interstate 40. 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 (Briley Parkway), about 0.56 miles (900 m) 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.
In the 19th century, much of the present-day route of US 31E was a stagecoach path between Louisville and Nashville, and before that a postal route at least by 1820.
When the rerouting of US 31E in Nelson and Spencer Counties was being planned, a survey of historic sites that could have been affected by the new route was studied, especially if the sites could one day become listed on the National Register of Historic Places.
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 in Southern Indiana
US 31E and US 31W once terminated at US 31 in Sellersburg, Indiana until 1980. US 31E followed the current routing of US 31 from Sellersburg to Louisville.
Rerouting of US 31E in east Nashville
In Nashville, US 31E once followed Gallatin Pike through east Nashville. Sometime after 1997, US 31E was rerouted onto Ellington Parkway.
Dangerous segments
US 31E has been known as a dangerous road, with many risky spots. A historic one was at Coxs Creek in Nelson County, where a post office had to be relocated so traffic could see each other. Other dangerous spots in Nelson County where emergency personnel consider notorious are Gobel Lake Curve, Hibbs Lane, and High Grove. As of August 23, 2017, the Hibbs Lane and High Grove reroute sections are almost complete and are in service. Minor work is still being done to some intersections and signage.
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.
U.S. Route 31EX (US 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 2.487 miles (4.002 km) long. At the intersection with KY 44, US 31EX is incorrectly signed as a Kentucky state route.