 Until 1980, all traffic following the A4 had to leave the M1 at its final junction and travel through Dungannon town centre to rejoin the A4, but a by-pass opened that year continued the A4 route ahead past the final junction of the M1, including a short section of dual-carriageway which had been built at the same time as the construction of the M1 itself.The A4 dual carriageway then continues, bypassing the hamlets of Granville, Cabragh and Ballyreagh, as well as the village of Ballygawley.At the Ballygawley Roundabout the dual carriageway ends and the A4 meets the A5 Derry-Aughnacloy road.