M12 Motorway
Route South from M1 motorway at junction 11 to A3 Northway, Portadown

M1 motorway

Length 2.7 km / 1.7 miles (but see note below under "route description")
Width 2+2 lanes

In two phases in 1967 and 1970

(West facing sliproads opened 1991)

Cost 2m (24.3m in 2005 prices) for original scheme
See Also

M12 on CBRD

Network map on this site

History of motorways on this site

Built to speed traffic from the M1 to the new city of Craigavon, the M12 is instead today a short spur leading to the A3 Northway in Portadown. This page has a number of elements:

History | Junction Map | Construction Timeline | Route Description

Ghost Junction | Traffic Data | Photographs


In the 1960s the Northern Ireland government decided to build a new city to offset the growing regional dominance of Belfast and to accommodate the growing population. The city had to be far enough from Belfast to be an independent economical unit, but close enough to encourage Belfast people to move there. The site designated in 1965 was the area of land on the 8km / 5 mile stretch between the towns of Portadown and Lurgan. It was to accommodate two new centres (called Brownlow and Mandeville) as well as a new retail core which, combined with the existing towns, would constitute a new city with four suburbs. The plan was to run a large dual-carriageway (known as the Portadown Urban Motorway, although it was unlikely that it was planned as a true motorway) from Portadown to Lurgan along the route of the railway. After the city was well developed, a second mirror road would be built on the south side. The M1 was being built to the north of this whole area and it was decided to link the two. A road link was planned to cover the 2.5km distance between the M1 and the Portadown Urban Motorway. The link would then extend south between Portadown and Mandeville and untimately terminate on the B3 Lurgan to Gilford road. Since the north of this road would lead to the M1, this last section had to be a motorway, and became the M12. Contrary to speculation, I don't think there was ever a plan to extend the motorway restrictions beyond the Carn junction (j2) as a map from the period shows several junctions that would be far too close together for a motorway. I believe the motorway restrictions were only going to be applied for legal reasons on the stretch that led inevitably onto the M1:

Contemporary concept plan of the M12 from the M1 (top) to the Portadown Urban Motorway (double line) and the extension of the route to the south east. Portadown is on the bottom left, with Mandeville to the right. Most of what is shown here was never built. [From Craigavon New City: Second Report on the Plan, March 1967].

In the end, the city was a failure, mostly due to wildly overestimated population growth figures, and of the two new suburbs planned, only Brownlow was begun. The Portadown Urban Motorway was only built from Portadown to Brownlow and was constructed as an at-grade single-carriageway road, now the A3 Northway. The M12 was built along with the east-facing sliproads connecting it to the M1 to Carn Road and opened in November 1967. The Carn junction was built as a fully grade separated roundabout with space for the M12 to pass beneath. Two and a half years later, the Northway was extended and a single-carriageway link road was built from the M12 at Carn to the Northway via what is now known as Kernan Loop. This road was never upgraded, and the route has never been extended any further south. In 1991, the west-facing sliproads were added. The necessary bridge had been built in 1967, but had laid derelict since then. Instead of the freeflow links planned (see map above), the new and old sliproads were joined by a roundabout. This roundabout was inexplicably numbered junction 1, even though it's really part of M1 junction 11, and the Carn junction renumbered junction 2.

Junction Map


Begins at M1 junction 11


M1 motorway west

M1 motorway east


1.7 km / 1.1 miles - 2+2 lanes


(originally j1 when built)

B2 Seagoe Road
B2 Carn Road

Terminates as M12-A3 single-carriageway link road


Construction Timeline

M1 eastbound to Charlestown Road 27 Nov 1967
Charlestown Road to Carn and on to Northway 9 Jun 1970
M1 westbound slips added 1991

Route Description

The length of the M12 is given above as 2.7km. However, the length depends on how you count it. The length of 2+2 motorway between the roundabout at junction 1 and junction 2 is 1.7km long. The two sliproads from here to the M1 eastbound are part of the M12, even since the west-facing slips and roundabout were added. Counted as one road, they are 1km long. And since we are counting this way, the new west-facing slip roads, counted as one road, are 0.8km long. So the total length of the road is 3.5km. However, the maximum length that it is possible to travel in one sequential journey on the M12 is 2.7km, so that is what is included above.

Starting on the M1 at Ballynacor, the M12 begins as two sliproads about a mile apart on some very low, flat land on the River Bann flood plain. The sliproads all swing south to the 1991 roundabout, junction 1. This is the only roundabout under motorway restrictions in Northern Ireland and, while not illegal, is certainly an anomaly since motorways are intended to be free-flow routes. There are currently no plans to grade-separate junction 1. Coming off the M1 westbound onto the M12, look out for an area of tarmac on the left that suggests that there may have been a plan to run a sliproad off here onto the local road network, an idea that has been floated periodically since without much action. There then follows a gentle curve 1.7km long before we come to junction 2, Carn, which may have briefly been a terminus in 1970 - I need more information to say for sure. The road then reverts to a single-carriageway and squeezes under the west side of the Carn roundabout bridges. Oddly, the "Start of motorway restrictions" sign occurs under the roundabout. Technically, they should begin at the previous offslip since motorway restrictions cannot begin at a point where non-motorway traffic cannot leave the road. The road travels on for another 800 metres to go round a 180 degree curve and join the A3 at a set of traffic lights.

Ghost Junction

There is evidence of an unbuilt "ghost" junction on the M12 on the sliproads between the junction 1 roundabout and the M1 to the east. On the northern sliproad (M12 > M1 eastbound) there there is a stub on the right for a sliproad joining from the right. And on the southern sliproad (M1 westbound > M12) there is a stub on the left for an onslip. Given that even today there are people calling for a link to the local road network from here (presumably to give direct access to the Rushmere area of Brownlow) it seems likely that there was once a plan to build such a junction here. However, the plan never made it off the drawing board. You can tell that the plan was very early because it involved a right-hand merge, a feature that was included in several early 1960s plans for NI motorways*, but abandoned shortly afterwards. Today both stubs are favourite haunts for police camera traps, but they can't have been designed for that purpose as mobile speed camera were not invented then. It is still possible that such a road link will be built, but at this stage it is more likely to join the junction 1 roundabout.

*Featured extensively in the Belfast Urban Motorway plans, and also for the unfinished M22/M2 junction.

Traffic Data

According to the "Craigavon Council Updating and Screening Assessment 2006", traffic levels on the M12 at junction 1 were 20,951 vehicles per day.


The start of the M12 motorway seen from the junction 2 bridge in 2006. The bridge is wide enough for a full motorway to pass beneath, so there was clearly a plan to extend the M12 that never happened. [Photo by Wesley Johnston]

The M12 junction with the M1 looking west soon after completion in 1967. Note that Ballynacor is incorrectly spelt on the image. At this point the M12 ended abruptly at the B2 Charlestown Road, and was not extended until 1970. [Image from the UK Motorway Archive Trust].