|This article does not cite any references or sources. (February 2009)|
|South end:||US-31 / US-31E / US-41 / US-431 in Nashville, TN|
|North end:||US 31 / US 31E / US 60 in Louisville, KY|
U.S. Route 31W (US-31W) is the westernmost of two parallel routes for U.S. Route 31 from Nashville, Tennessee to Louisville, Kentucky. At one time, it split with U.S. Route 31E at Sellersburg, Indiana, crossing into nearby Louisville via the Kentucky & Indiana Terminal Bridge.
The highway passes through Goodlettsville and White House, Tennessee; and Franklin, Bowling Green, Cave City, Horse Cave, Munfordville, Elizabethtown and Radcliff, Kentucky. It passes within a half mile on an entrance to Mammoth Cave National Park near Park City, Kentucky. It also passes through Fort Knox near Radcliff, within sight of the U.S. Bullion Depository.
Most of US-31W's route was part of the old Dixie Highway from the National Auto Trail program, the predecessor to the United States Numbered Highways system. Many of the cities through which US-31W traverses still give it a local street name of "Dixie Highway" or "Dixie Avenue." Some portions date back further, to the Louisville and Nashville Turnpike, which began construction in the 1830s.
Interstate 65 closely parallels US-31W from Nashville to Elizabethtown, and interchanges with I-65 several times. US-31W intersects with the William H. Natcher Parkway at Bowling Green, the Wendell H. Ford Western Kentucky Parkway at Elizabethtown, and Interstate 264 (Watterson Expressway) in Louisville. It crosses US-68 and US-231 at Bowling Green, and US-62 at Elizabethtown. It overlaps with US-60 from Muldraugh, Kentucky to Louisville.