Posted by: wesleyjohnston | October 7, 2012

The Unsung A6 Castledawson Bypass

There are many unsung heroes amongst Northern Ireland’s roads. While some bypasses are very well known, like those skirting Newry, Toome or Holywood, others languish in obscurity, quietly speeding motorists to their destination without so much as a by-your-leave.

The A6 Castledawson Bypass is one such unsung hero. Taken for granted by most travellers on the Belfast-Derry route, it seems like it’s been there for ever. It is hard to believe that in autumn 2012 (I do not know the exact date) it merely celebrates its twentieth birthday. The road is barely out of its teens…

For those who aren’t quite sure what I’m talking about, this map highlights the Castledawson Bypass, which opened in autumn 1992:

Prior to its opening, the A6 followed a quite different route, that took travellers right down the main street of Castledawson, as shown here:

Now, Castledawson is a lovely town with lovely people. As they say, some of my best friends live in Castledawson. Nevertheless, its main street is not a fun place to be if you’re trying to get from Derry to Belfast or vice versa. The one and only time I have ever driven through Castledawson took me about half an hour as two lorries had got stuck trying to pass each other on the main street. I am sure the locals dislike this as much as I did.

Castledawson main street, 2007. Image from Geograph © Copyright Kenneth Allen and licensed for reuse under this Creative Commons Licence:

If you can visualise all Derry-Belfast traffic trundling down this road, you can see why the opening of the Castledawson Bypass in 1992 was so welcome.

But this is Northern Ireland, so it goes without saying that the Castledawson Bypass is actually the end result of a long saga of half-finished road schemes and abandoned grand plans. Which, of course, just makes it all the more interesting!

Before the 1960s

Let’s go back to the early 1960s. Life was simple, traffic was light. The Troubles were yet to kick off. People danced to the Beatles. Much of Northern Ireland’s road system was still as it had been in the nineteenth century, with just the addition of tarmac. At this point the main A6 from Belfast to Derry ran to the NORTH of Castledawson, along what is now an unclassified road running through Moyola Forest:

Back then the long stretch of good single-carriageway road that runs west from Castledawson, past Knockloughrim and Maghera did not exist. You can see the route the A6 took back in 1961 by having a look at this historic map over on SABRE maps.

Grand Motorway Plans

In 1964, the Northern Ireland government announced a very ambitious programme of motorway building. This would see a whole series of motorways build across the east and north of the province. The plans were scaled back a bit in 1969, when it was realised that some were totally unnecessary. This map shows what was planned at that time:

Northern Ireland Motorway Plans as of 1969

Traffic from Belfast to Derry was to travel along the M2 and M23 motorways via Ballymena and Limavady. However, a spur motorway, known as the M22, would divert from the M2 at Antrim in order to serve the Mid Ulster area. It was planned that this motorway would terminate between Castledawson and Magherafelt. The map below shows the approximate planned route of the M22:

For those really interested, this is a scan of a map from the late 1960s also showing the M22 as proposed (although mis-labelled as M2)

This was all hunky-dory. Work on the M22 in 1968. Junctions 1 to 2 (bypassing Antrim) opened in 1971, and junctions 2 to 3 (bypassing Randalstown) in 1973. All seemed well…

Grand Plans for the A6

Not content to wait for the aspirational M23 to Derry, which was likely to be many, many years in the future, in the early 1960s the Londonderry county roads authority made grand plans to upgrade the entire A6 from Castledawson to Derry to high-quality single-carriageway standard. This is a task that they accomplished admirably, as you can see by comparing a stretch of the new road with what it replaced. No comparison. And nice, shiny hard shoulders to boot: something that is very common on single-carriageway roads in Northern Ireland, but much rarer in the rest of the UK.

One of the most ambitious parts of the A6 upgrade was to build a completely new stretch of road between Castledawson and Maghera, a distance of about 8 miles (13 km). This road replaced one of the worst parts of the existing A6, and was also designed to tie in to the terminus of the M22 which was to be on the A31 between Castledawson and Magherafelt. Thus, the upgraded A6 was routed to the SOUTH side of Castledawson, even though the rest of the A6 towards Belfast began on the NORTH side of Castledawson.

This stretch of road was built in four phases between 1969 and 1971 (ish) at a total cost of £1.2m (roughly £12m at today’s prices). Because this road arrived before the M22 did, the planners went ahead and built the M22’s terminal roundabout and connected their new stretch of road to it. This roundabout is what is familiar to most drivers today as the Castledawson roundabout. So confident were they that they even built the first few dozen yards of the M22 away from the roundabout. People who recall using the roundabout in the 1970s may remember this strange little stub of road.

Of course, this created a situation where traffic suddenly had to drive along Castledawson’s main street to continue on the A6. It must be one of the few situations in UK road-building history where a trunk road that previously went harmlessly past a town was diverted onto the town’s main street, rather than off it!

But that the time this wasn’t a big concern, since the M22 would be completed by the mid 1970s. The planners then sat back and waited for the M22 to arrive. And waited….

Plans Scaled Back

In 1972 the Northern Ireland government collapsed, and the grand motorway plans soon followed. All work on the M22 halted, leaving Mid Ulster’s motorway ending awkwardly at Artresnahan on the Moneynick Road, just west of Randalstown. Thus the people of Castledawson had to tolerate the A6 running down their main street for the next two decades, while the little stub of M22 at the Castledawson roundabout taunted them with thoughts of what might have been. Drivers, too, were forced to drive along the twisty Moneynick Road and inch down Castledawson’s main street. The situation was not good.

This is a photo of an historic map showing how the area looked in 1981:

Castledawson area in 1981, showing how the A6 runs along Castledawson main street. Also showing the M22 “stub” at Castledawson roundabout.

By the mid 1970s it was clear that, for financial reasons, the motorway system was not going to happen in the near future. Roads Service (formed in 1973 by merging all the various roads bodies) decided to press ahead with a much more modest 2.1 mile (3.5 km) bypass of Castledawson [1]. Intitially planned to be in place by 1982, the scheme was delayed again, and again, and again. Work finally began in 1991 and it opened to traffic in autumn 1992. The total cost was £2m (around £3m in today’s money) and the contractor was RJ Maxwell.

Because it was built on a budget, the Bypass features priority T-junctions with right-turn pockets along its length, for example here at Annaghmore Road. One of its most impressive features is the 3-span reinforced concrete bridge over the River Moyola, which is sadly unappreciated due to a lack of any nearby vantage point:

The Castledawson Bypass that was eventually opened in 1992 was a much smaller-scale road than was anticipated when the Castledawson roundabout was built around 1971. This meant that the few dozen yards of M22 that had been built there had to be quietly bulldozed and replaced by the more modest single-carriageway road. However, the road here is on a slight embankment, and the M22 stub lives on in the form a very over-engineered section of embankment adjacent to the roundabout, that was originally intended to carry the M22. It’s hard to see in Google Maps, so I’ve highlighted the edge of the embankment here:

The Next Stage of the Story

Since the bypass opened in 1992, the situation has changed again. The Troubles are over, and more money is available once again. Now there is a desire to finish what was once started and complete M22 to Castledawson, albeit in the form of a high-quality dual-carriageway A-class road. This means upgrading the existing Castledawson Bypass by adding a second carriageway to the south of the existing road, which will then become the eastbound carriageway. All the side-accesses will be closed up and replaced with two grade separated junctions – one at Hillhead Road, where the Castledawson Bypass departs from the line of the original A6, and a second to serve Annaghmore Road and Bellshill Road. The Castledawson roundabout will remain as it is, except that the approach embankment will have to be widened to accommodate a dual-carriageway (well, now!). Here is the plan as it currently stands:

A6 dualling proposals as of 2012

For those who fancy delving in in more detail, have a look at the coverage of this scheme over on my web site.

At the time of writing the scheme is on hold until at least 2015, and we know from experience that it might take longer. Will the Castledawson Bypass see its 30th birthday in its current form? I hope not, but with the recession, who knows?

In the meantime, let’s pause for a moment to appreciate the Castledawson Bypass and the benefits it brings to both travellers and the residents of Castledawson every day. Cheers!


With thanks also to my friends over on SABRE for the many discussions about this road.



  1. Yet another fascinating article, Wesley. Don’t remember the M22 stub at Castledawson, as I was never over in that area before the bypass was built. Despite that, it’s nice to have my suspicions confirmed about where certain parts of the old A6 used to run.

  2. […] However, the fact that the grand motorway plans of the 1960s were never completed left some problems with the A6 upgrade. Firstly, it ended south of Castledawson, at the roundabout where the M22 was to end, rather than passing the town to the north as the old A6 did. Since the M22 was never completed this far, it meant that all A6 traffic now had to go down Castledawson’s main street! This was very unsatisfactory and, after it was clear that the M22 was not going to be completed, a ‘quick fix’ in the form of the Castledawson Bypass was finally built in 1992 to resolve the problem. I talk more about this vital but under-rated bypass in this blog post. […]

    • It’s not too late to route the a6 north of Castledawson via hill head as it was originally ,this would take the traffic away from the bottleneck at the Castledawson roundabout . If this Had been done at the outset and the new route joined to the a6 a few metres north of curran bridge this would have saved the cost of two bridges over the Moyola river.Perhaps someone in government then in the 1960s didn’t want the road made through their land . Have you been in Castledawson lately traffic is still heavy as the bypass does nothing for traffic passing east to west ie. bellaghy Magherafelt

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