On the north side of Lewisburg, US 31A splits off, and then a few miles later SR-50 splits off, while US 431 and SR-106 jointly continue north. The route pair, variously known through this section as Lewisburg Pike or Franklin Pike, eventually passes underneath Interstate 65 to enter the town of Franklin. Continuing north, the route pair passes through the exclusive Nashville subdivision of Brentwood before entering Nashville proper. The route skirts the campus of Vanderbilt University before entering downtown Nashville from the southwest. Crossing under Interstate 40 (where SR-106 ends), the route follows Broadway to its intersection with Rosa L. Parks Boulevard. Here the route makes a left turn towards the northwest, joining with U.S. Route 31 and U.S. Route 41 and several state routes. The route snakes around the state capitol and crosses the Cumberland River going northwest as James Robertson Parkway. In east Nashville, the route crosses under Interstate 24, then follows Spring Street and then Dickerson Pike northward.