Northern Ireland boasts the oldest integrated motorway system in Ireland, amongst the earliest motorways in the UK, and what was for many years the widest motorway in the UK. Yet, as they were never completed as intended, our motorway numbering system seems illogical to outsiders and is often confusing for drivers who live here. Plans for future junctions will put further pressure on a numbering system now over 40 years old. The current Westlink upgrade provides a rare opportunity for a review of motorway numbering in Northern Ireland: to re-number the motorways and their junctions in a more logical and future-proof manner.
Rationale for Change
Northern Ireland's motorway numbering system was based on the plans of 1964 which were never completed. So while they made sense at the time, we are now in a situation where the motorway numbers are confusing. For example:
- The M2 becomes the M22 at Antrim giving the appearance of two junction 1's on the route, and an arbitrary number change; a situation which makes no sense to most drivers.
- Short spurs such as the M5 have single-digit numbers while the much longer M12 and M22 have two-digit numbers.
- Numbers of abandoned motorways are missing, such as the M11 and M21.
- There is too much use of 'A' and 'B' designations to clarify junction numbers, most obviously the first three junctions on the M2 which are numbered 1A, 1B and 1. Planned junctions between j4 and j5 on the M2 and j8 and j9 on the M1 will compound this issue.
With the A12 Westlink currently (Jan 06) being upgraded to fullly grade-separated standard, it will soon flow directly onto and off the M1. It seems very clear to the public that it is, for all practical purposes, part of the M1. Given the fact that the M3 was built to urban motorway standard with reduced hard shoulders and tighter curves, and given that some motorways in Britain have no hard shoulders at all, there is no real argument against doing this with the Westlink.
In England and Wales five principal motorways leave London radially and are designated, clockwise from the north, M1, M2, M3, M4 and M6. The M5 runs further west than London. These six motorways then form the edges of "zones" of numbering. Anything within a zone has that number as a prefix. So, for example, the other motorways in zone 4 are called the M40, M42, M48 and M49. These numbers are logical and help road users to unconsciously know where a given motorway should be in the country. Also, the secondary motorway often leads to the primary motorway (although in quite a few cases it does not).
In Scotland and the Republic of Ireland, by contrast, motorways are designated by the number of the primary route that they replace, or bypass. So the M8 in Glasgow replaces the A8 route, and the M3 in the Republic of Ireland replaces the N3 road. The motorways either in existance or being planned in the Republic of Ireland are the M1, M3, M4, M6, M7, M8, M9, M11 and M50.
The original numbering strategy in Northern Ireland was for the principal routes to be designated M1-M4 clockwise from the west. The addition of proposals for the M5-M8 muddied this simplicity as they were interspersed between the first four. The plan was that spur motorways would come off these and be numbered the same as the parent motorway but with an additional number, hence M11, M12, M21, M22 and M23. This is how the Northern Ireland system got its current motorway designations. While this system made sense at the time, it makes little sense now that most of the original plan has been abandoned. In addition, our insistance that spurs should be numbered sequentially without gaps (eg M21, M22, M23 etc) is a degree of strictness not found anywhere else in the UK, where any two-digit number within a zone is available for use (witness M40, M42, M48, M49 but not the other 6 possibilities). This requires less long-term planning.
A Strategy for Northern Ireland
There is a good case for numbering our motorways in conjunction with the authorities in the Republic of Ireland because we all share an island and motorists see less significance to the border than politicans do. However, it is also recognised that this is a contentious issue that deals with much more than just road numbering. So what is proposed is a "future proof" numbering system, one that is designed for Northern Ireland as a self-contained entity, but which could relatively easily be converted to an all-Ireland numbering system if that is what the two governments decide.
A new numbering strategy should therefore:
- Be based on a small number of strategic motorways with secondary spurs.
- Number motorways the way drivers see and use them.
- Have a single geographic location as the point of origin for the whole system.
- Eliminate 'A' and 'B' junction numbers.
- Future proof, ie able to be integrated into an all-Ireland numbering system.
- Take into account, within reason, the possible future addition of junctions.
Principal Numbering Proposals
The primary proposal of this document is to base the entire system at a single location, the York Street junction, and designate this "junction 1". This would provide a single, recognisable point of origin for Northern Ireland's entire motorway system. All three motorways that leave this point would have single digits. All remaining motorways would be designated secondary to these three. Such a system would quickly become familiar to the travelling public who would unconsciously know roughly how far any junction was from York Street by its number.
The implication of this for the Westlink leads to proposal number two, that the A12 Westlink be incorporated as part of the M1 once the current upgrade is completed. The result of this relatively simple move would be that the existing M1, M2 and M3 would all meet at this single location. The junction would be junction 1 of the entire system.
With future integration with the Republic of Ireland's motorway numbering system in mind, we note that the M1 in the south is designated as the main route towards Belfast. Therefore, no matter what happened in the future, the M1 at the Belfast end would in all likelihood retain the M1 label. The M2, however, is one of only two primary numbers that not used in the Republic, so it would make little sense at this late stage for the Irish NRA to create a duplicate M2. This leads to the third proposal, that the Irish National Roads Authority avoids using the designation M2 which should be reserved for its existing use in Northern Ireland. Future use of the label M3 is discussed in more detail below.
Secondary Numbering Proposals
The numbering of the secondary motorways, then, should be based on the primary motorways M1, M2 and M3. Adopting the British system of "zones" would give us three numbering zones, as shown below. Zone 1 would include everything south and west of Belfast, zone 2 everything north and west, and zone 3 everything east of Belfast. All secondary motorways in each zone would be two-digit and use the zone number followed by a second digit. This system has the advantage that it allows most of the motorway system to retain its current numbering, minimising disruption, while still providing a more logical framework for numbering. Detailed proposals for each zone are given below.
Zone 1 Proposals
The current motorways in zone 1 are as follows:
- M1 motorway from Broadway to Dungannon
- The existing M12 spur to Craigavon
- The Westlink from York Street to Broadway
The main proposal is to subsume the Westlink into the M1 since most drivers do not see a distinction even before the upgrade, and this will be even less once it is fully grade-separated. Other than this, there seems to be no good case for changing the designations of the M1 and M12, as the M1 is already the primary motorway, and the M12 is correctly numbered for a secondary motorway in zone 1. In any case, the M11 number is already used in the Republic of Ireland.
The proposed motorways in zone 1 are therefore:
- M1 motorway from York Street to Dungannon
- M12 spur to Craigavon
Zone 2 Proposals
The current motorways in zone 2 are as follows:
- M2 motorway (main section) from York Street to Antrim
- M5 spur to Whiteabbey
- A8(M) spur to Corr's Corner
- M2 motorway Ballymena bypass section
- M22 motorway as the continuation of main section of M2 on to Randalstown
The numbering system here was originally highly logical when the M2 was intended to go to Coleraine, the M5 to Carrickfergus and the M22 to Castledawson. However, with the abandonment of these plans, the numbers are confusing to motorists and a source of derision to those living outside the province. The motorways should be united around a simplified M2 with the others designated with two digits. The fourth proposal of this document is therefore to combine the existing main section of the M2 and the M22 into a larger M2, and redesignate the M5 and M2 Ballymena bypass as the M20 and M21 respectively. The A8(M) is a different class of motorway, numbered this way as it is really the A8 with motorway restrictions. This designation should not change. The M22 number would cease to exist which would prevent the confusion which would occur were it to be used elsewhere.