I don't know how you're keeping yourself occupied during the pandemic, but I sometimes fill the time by asking pointless hypothetical questions. Like this one.
How far could I drive by following an increasing sequence of road numbers?
I live on the A11, so that would be my first road number. My next road number would have to be greater, for example the A12, which is convenient because these two roads interchange at the Bow Roundabout.
Numbers don't have to be consecutive so I can stay on the A12 all the way to Ipswich and change there for the A14. This takes me to Kettering where I can switch to the A43, then turn left onto the A47 near RAF Wittering, then change in Nuneaton onto the A444 to Burton-on-Trent. But my choices here would be somewhat limited so the best I could do is follow the A511 to its last junction just east of Uttoxeter. The only other road here is the A50, so numerically I'm now stuck, but I did manage to end up 118 hypothetical miles from home.
If I lived on the A1 I could have done a lot better... A1, M1, M6, A7, A8, M9, A9, A836, John O'Groats. But because I live on the A11 none of the single digit trunk roads and motorways are available which cuts out a lot of the most advantageous routes. Also the A7/A8 connection in Edinburgh only works if you accept historical alignments because Princes Street has been declassified, and these are the pedantic minutiae upon which today's challenge turns.
I was sure I could do better than 118 miles so kepttrying until I found a much longer route. I'm totally resigned to the fact that at least one of you is going to pick a hole in it. The road network has many topological imperfections, your local knowledge is much better than mine and there's bound to be a cunningly better route. But here's my best attempt as I hypothetically drive from Bow to the Scottish Lowlands along roads whose numbers only ever increase.
A11 → Bow Roundabout A12 → M25 Junction 28
The only rational start.
M25J28 → J13
That's anti-clockwise via Hertfordshire, because clockwise would require crossing the Dartford Bridge and this is officially the A282. Intersecting roads with two-digit numbers include the A41, M40, A30 and M26. But the A41 fades out in Bicester and the M26 is a numerical dead end, so not those. The M40 joins the M42 in Birmingham, then joins the A50, all of which looked promising but I got a bit stuck in Stoke. The M40 also joins the A40, and this goes all the way to Fishguard in Wales which is 215 miles from home. But by leaping into the forties prematurely I have harmed my ability to move up-country, so it turns out the A30 is the best way to go.
A30 → Yeovil
The A30 goes all the way to Lands End in Cornwall, which is an impressive 268 miles from Bow. But the A30 also crosses a lot of A-thirty-something roads so that's the way I intend to go. The A34 is the king of the north-south trunk roads but has a big gap between Bicester and Solihull so is of no immediate use. The A38 is almost as long but has been swallowed by the M5 for 14 miles just north of Exeter. Technically this is called 'multiplexing', where two designations share the same road, so I could argue it counts as a continuous road. But best take an alternative route with fewer technicalities along the way.
A37 → Bristol A38 → Alfreton
The A37 takes a less contentious route to Bristol where I can finally join the A38. This phenomenal trunk road runs from Cornwall to Nottinghamshire, shadowing the M5 a lot of the way. At Spaghetti Junction it briefly becomes the A38(M), but according to my rules that's OK. I've also decided to be comfortable with any brief stretches of multiplexing along the way. And this brings me to the East Midlands while still somehow in the 30s, which enables me to switch to my next key route.
A61 → Leeds
The A61 runs almost directly due north through Sheffield, Barnsley, Leeds and Ripon, so is ideal for my purposes. I'm going to jump ship in Leeds, where I need to plead for the use of historical alignments through the city centre to enable my next connection.
If you insist on me using the modern road pattern in Leeds, ring roads and all, then I'd be forced to drive on to Thirsk, follow the A167 through Newcastle and take the A189, A1068 and B1340 to Bamburgh Castle in Northumberland which is 291 miles distant. But I'd rather not.
A65 → M6 junction 36
The A65 delivers me across the Pennines to Cumbria, in part following the Settle to Carlisle railway. But I'm not allowed to follow the M6 or the A6 to Carlisle so I need to take the scenic route instead. And for this I finally need to exit double figures.
A590 → A591 → A595→ Carlisle
The A591 is the road through the heart of the Lake Distrtict skirting Windermere and Grasmere, so this part of my hypothetical drive is properly gorgeous. The scenery recedes somewhat after Keswick, and even more so as I approach Carlisle from the west.
A689 → Brampton A6071 → Gretna
The only roads between Carlisle and Scotland are the M6 and the A7, neither of which are permitted, so I need to follow the bypass east to dogleg back through Brampton. Technically the Brampton bypass means the A689 and A6071 no longer meet, but they once did, and they only miss by half a mile of unclassified road today so I'm having that. Time to cross the border.
B7076 → Elvanfoot
Last road. And because numbers are now against me it's only a B road... but what a B road. Thomas Telford built some of it. The B7076 runs alongside the A74(M), the motorway north to Glasgow, and used to be the A74 dual carriageway. In most places one carriageway has been returned to grassland and the B7076 follows the other on a winding course across the moors. It finally draws to a close after 44 miles at Elvanfoot, a small village at the head of the Clyde valley, where the A702 takes over.
I can go no further without using a road with a lower number. But I am now 310 miles from home which is as far as I think I can hypothetically get.
What's more I've driven more than 600 hypothetical miles to get here, on a ridiculously tortuous route via Somerset, Derbyshire and Cumbria. At least I can get the West Coast Main Line home because trains pass this very spot. There may not be a station, but hypothetically I can imagine there is and abandon my hypothetical car on the hard shoulder.
It'd never be worth trying in real life, but a hypothetically increasing road journey is one way to pass a day indoors.
