Sorry, wrong number

Road numbering is a system with clear rules. Unfortunately the people responsible for numbering roads don't always follow them - or even, sometimes, seem to care there's a system at all.

Our year of celebrations to mark the centenary of UK road numbering has run on for slightly more than a year now - but who's counting? We're bringing the season to a close by exploring some incorrect and unhelpful numbering mistakes.

You wouldn't think it could go too badly wrong. Not only does the system come with rules to tell you what sort of number is appropriate in different situations and different parts of the country, there are also literally thousands of examples that demonstrate how it looks when it's done right.

Then again, maybe the fact that it looks easy is why it isn’t taken very seriously.

You might think a badly chosen number doesn't matter, and sometimes it doesn't. The present A42, for example, was applied to a road between Tamworth and Nottingham in the 1980s. It lies entirely within zone 5, so it should have a number beginning with a 5, so it’s technically wrong - but the downsides of calling it A42 are few, and outweighed by the navigational benefits of it forming a continuation of the M42. Choosing a number that breaks the rules, for pragmatic reasons, might be a good choice. The world still turns.

What we're here to discuss is much more interesting: bad numbers that were created for terrible reasons, or even for no reason at all. By looking at them in detail we might learn a little bit about why road numbering actually matters. But first, let's take a moment to remember how numbering is meant to work.

An internal memorandum between civil servants at the Department of the Environment in 1972, discussing potential motorway numbers south east of Birmingham, where you might expect to find a number like M41, explained the problem with this number:

The phrase "became attached" sounds almost delightfully accidental. It's easy to see what happened: it was meant to be M14, but at some point the digits were accidentally transposed, and since M41 appeared to fit nicely in West London, surrounded by 4-zone numbers, nobody thought anything of it until it was too late.

In 1973 it became clear that the rest of the West Cross Route would never be built, and the jumbled number remained in service until the stump of road lost motorway status about 26 years later.

Saved by roadgeeks

Here’s a very different kind of mistake. In the summer of 2011, Birmingham City Council opened a long-awaited bypass for Selly Oak, diverting the A38 away from the main shopping street. The old road, vacated by through traffic, was downgraded to a B-road. It needed a new number.

Its new number was B38.

Once again, the vigilant members of SABRE swung into righteous action, composing messages to Scotland’s trunk road authority to ask whether this was some terrible mistake. This time, though, the authorities were not to be swayed. Scotland no longer cares about the century-old rules.

That is true: road numbering and signage are devolved matters, so Scotland is not beholden to Westminster, or anyone else, when it chooses numbers for its roads. They could have called the old road through Maybole the X5000 if they wanted, or Highway Z, or Route Four Billion, and nobody can tell them not to.

However, this is the first time that Scotland has actually done anything other than follow the rules established for the whole of Great Britain a century ago. (A pedant might also note that, while Scotland has the power to make its own numbering policy, it has never actually done so, and as far as anyone can tell its current policy is unchanged from the one it inherited in the 1990s, which permits only three- and four-digit B-road numbers.)

However, in early 1980, the final section of M876 opened to traffic, bypassing the old A876 through North Broomage and Antonshill. As is common, the old road was renumbered to remove the association with the number 876 and encourage through traffic onto the new motorway. But instead of a demotion, for reasons known only to themselves, Scottish highway engineers gave the bypassed length the unused number A88.

The result is that the old road, trundling through the towns of Stirlingshire, has the important-sounding and catchy number A88, while the high speed trunk road just to the north is lumbered with M876.

Why not just renumber the whole road to A88, which would permit this vital link in Scotland’s motorway system to be called M88?

No logical reason for this decision has ever been found, no official explanation has turned up to explain it, and nor does the open goal of M88 ever seem to have been considered. But then, if you go looking for logic in British road numbering, you’ll quickly find there’s none in sight.

Mistakes happen, of course, and the world muddles on regardless whether Britain has short lengths of road numbered B77 or B38 or M14 or M88. But all too often numbering is treated as an irrelevance or an afterthought, even by the professionals who are tasked with upholding it.

If we’re going to use road numbers at all - and we evidently are - then we ought to credit them with at least a passing appreciation of the value they can bring.

Road numbers have now been part of all of our lives for 101 years: a part of our national furniture without which we’d see the world, and our journeys through it, very differently. Road numbers are clearly worth the trouble. So, perhaps, we ought to go to the trouble of sparing them a moment’s thought when we need to come up with a new one.