The A14 raises all sorts of questions. One of them is, how did we survive for so long without it? The route linking Rugby (and therefore the West Midlands and the north of England via the motorway network) to East Anglia and the ports of Felixstowe and Harwich is incredibly important and incredibly busy. And yet it didn't exist in any coherent form until about 1992 when the A14 popped into existence.
Most of the route is a mongrel collection of bits of dual carriageway poached from other roads (most notably the A45) and the occasional bit of new road to bolt it all together. Most of the key interchanges are, therefore, the wrong way round and the A14 uses them to turn a corner, causing furrowed brows and idling engines on a daily basis.
That raises the other question about the A14: how do we manage with a road that is clearly so bad at its job? Because of its varied heritage the road is narrow, badly aligned and mostly not actually built to do what it now does. The culprit, ultimately at the bottom of both questions, is the sudden rise in container shipping, and Felixstowe is the UK's principal container port. The A14 is the road between Felixstowe and everywhere else.
Before 1992 the A14 was a back road linking the A10 at Royston to the A1 at Alconbury, via Papworth Everard and Godmanchester. Today this road is the A1198, which connects to the A14 at junction 24. The only bit of the current A14 that follows the number's original route is the spur that links junction 23 to the A1.