US 31W begins in Nashville, at an interchange with Ellington Parkway and US 31/US 31E. The route continues west as Spring Street, concurrent with US 41/US 431/SR 11. The four highways continue north onto Dickerson Pike, closely paralleling Interstate 24 (I-24) through Nashville. At an intersection with Trinity Lane, all the routes but US 41 and SR 11 split from US 31W and continue west, while US 31W continues north, away from I-24. The roadway has an interchange with I-65 and SR 155 before an intersection with SR 45 in Bellshire Terrace. The highway passes through Goodlettsville, where US 31W splits from the other two routes and crosses I-65; it also passes through White House.