It traverses the city of Franklin, Tennessee before entering the Metropolitan Nashville and Davidson County area.

[2][3] In Nashville, US 431, known as Hillsboro Pike, traverses the exit 3 interchange on I-440, and eventually merges into US 70/SR 1 before entering the downtown area.

[2][4] US 431, now paired with a secret SR 65 designation, then follows Trinity Lane, crossing the I-65/I-24 exit 87 interchange, and turns right onto Whites Creek Pike.

US 431/SR 65 continues northward to traverse I-24's Joelton interchange, exit 35, before entering Robertson County.

It then splits off again, and US 431 continues north to the Kentucky state line, which marks the northern terminus of SR 65.