Back on some quiet afternoon in the 1980s, long before the internet and other distractions, I amused myself by trying to find all the two-digit A roads in a UK road atlas. The A34 was easy because it was on lots of pages, the A95 took rather longer, the A54 wasn't immediately obvious and the A67 wasn't where I was expecting it to be. But the A road that took the longest to find was in southern Scotland and it was tiny, much shorter than I thought main roads had any right to be, plus there were a few numbers I couldn't find anywhere at all. Life was a lot quieter back then.
The length of an A road is not necessarily a fixed amount. Designations change, certain sections may get downgraded and how should a complex dual carriageway be measured anyway. I discovered some of the potential anomalies yesterday when I tried making a list of the lengths of the first 99 A roads by compiling information from the internet. Alas many of Wikipedia's A road pages are length-less, and so are many of the pages on the SABRE portal, and annoyingly their numbers often disagree. For example Wikipedia thinks the A11 is 112.4 miles long whereas SABRE reckons it's only 61.8 miles because there's now a 50 mile gap between Newmarket and the Bow Roundabout. I had more confidence in SABRE data so chose to fill my spreadsheet with that, but I had to use Wikipedia to fill in the gaps... and basically what I'm saying is to take the following mileages and rankings with a healthy degree of scepticism.
The 10 longest single/double-digit A roads
1)A1(about 400 miles) London → Edinburgh 2)A38(about 300 miles) Bodmin → Mansfield 3)A6(just under 300 miles) Luton → Carlisle 4)A30(284 miles) London → Land's End 5)A9(279 miles) Falkirk → Thurso 6)A40(263 miles) London → Fishguard 7)A5(252 miles) London → Holyhead 8)A46(about 220 miles) Bath → Cleethorpes 9)A39(204 miles) Bath - Falmouth 10)A82(167 miles) Glasgow → Inverness
The A1 easily comes top, as befits the pre-eminent Great North Road. But only three other single-digit A roads appear in the Top 10, because a lot of double-digiters are actually longer. The A38 takes second place, probably, depending on how you measure it, otherwise it's the A6, but that might actually be fourth behind the A30. Roads heading for national extremities tend to be the longest, although it's intriguing to see Bath in the list twice and amusing to see Luton and Cleethorpes make the cut. Like I said don't trust this list too blindly, I bet you'd have ordered it differently.
Probably more interesting, and much easier to confirm, is the list of the shortest double-digit A roads. None of the single-digiters come anywhere close. I'll start with number 5 and count up to the really short one.
The 5 shortest double-digit A roads
5)A42(15 miles)Kegworth → Appleby Magna
The A42 is a major East Midlands link road, specifically in Leicestershire, connecting junction 23A of the M1 to the junction 11 of the M42. Essentially it's a continuation of the M42 motorway but without official designation. It's also fairly new, having only been completed in 1989, and this lateness helps explain its brevity. It's also not the first A42 because that ran from Reading to Birmingham, but only until 1935, and old and new don't even come close to overlapping.
That's it for England - from here on it's Scotland all the way.
4)A79(7.7 miles)Monkton → Doonholm
The A79 is essentially the road from Ayr to Prestwick Airport, but extended slightly to two lesser known termini. It took me ages to find in my 1980s road atlas because it's squished really close to the A77 (which forms the parallel Ayr bypass), and of course because it's really short. In no other sector of the country would there have been a double-digit number spare for an airport link road.
3)A80(7.2 miles)Glasgow → Mollinsburn
Originally the A80 went all the way from Glasgow to Stirling, which is more like 30 miles, forming a key road triangle with the A8 and the A9. But then the M80 got built in parallel - in three stages from 1974 to 2011 - and now all that's left is a stumpy A road that stops before it gets to Cumbernauld.
2)A74(7.1 miles)Glasgow → Uddingston
How the mighty have fallen. The A74 used to be the key route from Carlisle to Glasgow, a continuation of the A6. But starting in the 1990s the road through the Lowlands was upgraded to motorway standard, downgrading (and absorbing) the original route. It's now the A74(M) when it leaves Gretna and the M74 when it reaches Glasgow, arbitrarily switching in the middle of nowhere, and all that remains of the A74 is the last urban stretch (starting not far from the Tunnocks factory).
1)A88(3.5 miles)Larbert → Stenhousemuir
The briefest double-digit A road can be found skirting the northern edge of Stenhousemuir. The A88 started out in 1965 as a road feeding traffic towards a bridge across the Forth and was designated the A876 - a lowlier more appropriate number. Then in the 1970s the M876 was built nearby, so it was decided to change the A876's number to avoid confusing drivers, and the number 88 was still spare so for some reason the planners decided to call it that. It's not deserved, although it does make this single carriageway oddity the shortest double-digit A road in the country.
But the A88 is by no means the shortest A road in the country, indeed the very first three-digit A road utterly trumps it. The A100 is in central London and a miserable 1.2 miles long, although during that brief stretch it manages to be one of the most famous roads in the world. That's because it starts at Tower Hill, ends at Bricklayers Arms and along the way crosses Tower Bridge (bascules permitting). Of the first hundred A roads, the A100 easily wins. The A101 nearly beats it (that's the Rotherhithe Tunnel), but not quite.
But the A100 is by no means the shortest A road in the country. That honour, it's believed, goes to the A962 which is just 110 metres long. You'll find it in Kirkwall in Orkney, roughly between the cathedral and the bus station, under its official name of West Castle Street. It links the A960 at one end to the A963 at the other, and wouldn't be needed if Albert Street hadn't been semi-pedestrianised. And I'd never ever have spotted it in my road atlas because it was much too small to be marked, so hurrah to the internet for answering the questions my teenage self wasn't even able to ask.
