The A6 road in Northern Ireland runs for 71.4 miles (114.9 km) from Belfast to Derry, via County Antrim and County Londonderry. From Belfast to Randalstown the route has been superseded by a motorway (the M2 and M22). Mostly single carriageway, there are sections of dual carriageway in Antrim town centre and from Randalstown to Toome, including the Toome bypass. In urban and suburban districts of Belfast and Derry the route is single carriageway with 4 lanes (2 lanes in each direction). In rural parts, there are numerous climbing lanes along the route. The A6 is one of Northern Ireland's most important arterial routes, as the road runs between its two largest cities and urban areas. Between Randalstown and Derry the road forms part of European route E16. There is a new dual carriageway bet