Some A-roads are incredibly long. The A38, for example, runs for hundreds of miles in order to connect Bodmin with Mansfield. But not all of them.
Some A-roads are fairly short, perhaps only a mile or two in length. That's little enough. Spare a thought, then, for the surprisingly numerous group of A- and B-roads that are very brief indeed - less than a mile sometimes.
The A6118 was very short but very eventful. It branched off Britain's longest road, the A1, near Peterborough and ran from one end of the village of Wansford to the other. Then it stopped.
It appears to have only existed because, in 1929 when a bypass was built to carry the A1 past the village, normal practice was to leave the road number on the old road and give the bypass a new number. In Wansford the old road was so unsuitable for through traffic, and the new road so much shorter, that it made no sense to leave the A1 running through the village. So the A1 moved to the bypass, and perhaps because there was no established way to deal with the old road, it retained A-road status, becoming A6118. This little oddity then persisted for the following 88 years.
In 2017, perhaps in recognition of the fact that it served no meaningful purpose, it was downgraded and is now unclassified, holding no road number at all. This gallery of pictures, taken in 2009, shows pretty much all of it.
Travelling north on the A1, just past Peterborough, there's a little sliproad signposted for Wansford. Let's see where it goes.
Coming out of Wansford, you can only turn left to go north on the A1. (Or you can go through a gate to the right into the allotments.)
The road enters the village immediately and, though there's nothing to say it at this end, this is the beginning of the A6118.
At the village main street, there's a give way line and the A-road turns right. To the left is the B671 to Elton.
If this doesn't make much sense for the route of an A-road, the street sign gives it away. This is London Road, and until the 1920s it was the Great North Road. For a couple of years, between road numbers being introduced and the Wansford Bypass opening, it was the A1.
The main street is very wide here, in common with many other villages. At one time it would have held a market.
The junction where the A6118 and London Road turn the corner is marked by this less-than-helpful sign. Both arms have been swung round to face the wrong way. Ordinarily, "The North" would point east and "The South" would point north from here.
Here's why the village was bypassed so early on: the nine span single-track bridge over the river. A new bridge was provided just to the east for the A1.
Towards the end of the bridge, southbound traffic finds it difficult to see whether there is anything on the bridge already.
Then another oddity: give way again. For one kilometre of road, the A6118 is certainly not without activity.
Here's a better look at the junction, complete with huge zebra crossing. The road through here was the A47 long after London Road ceased to be the A1, which is why it takes priority here. Now that the A47 also bypasses Wansford, it leaves the A6118 ceding priority to an unclassified road.
At the other side of the junction, some minimalist signposting shows where all the major roads are now that they have vacated this crossroads.
Before much longer we're approaching the end of the line. Here are all those major roads again — the A47 bypass running east-west across the roundabout, and ahead sliproads to the A1.
The road opens out as it leaves the village. Even though it's been more than eighty years since this was the A1, it still has the air of a major road about it.
The roundabout is a relatively recent development, and has a rather out-of-place pedestrian subway underneath. It also has an unusual 60mph limit.
Inside the subway, artwork produced by local schoolchildren shows the village's handsome river bridge and describes the rerouting of the Great North Road to avoid it.