Glasgow International Airport (GLA) : Head west on Waterloo Street for M8. Exit M8 at Juction 28 for Glasgow Airport and follow the airport signs.
Prestwick Glasgow Airport (PIK) : Head west on Waterloo St for M8 and follow Glasgow Airport signs. Exit M8 at J22 for M77. Continue on to the A77 and follow Prestwick Airport signs.
Edinburgh Airport (EDI) : Head west on Waterloo St and take next left onto Blytheswood Street. At the end of the street turn right onto Argyle St, then take M8 for Edinburgh. At M8 J2 merge with M9. Exit at J1 for A8 and follow Edinburgh Airport signs.