M2 and A2

Despite its important-sounding number, the M2 is not very long and remains isolated from the rest of the national motorway network. When it first opened in the mid-1960s, it really was alone - it was built to bypass the slowest sections of the A2 on the long run through the Medway Towns. In those days, the rest of the A2 and much of the parallel A20 were just ordinary single-carriageway roads and the M2 was the fastest, widest, most extraordinary part of the drive. Today it's lost that distinction.

The M2 now forms just a section of the high-quality route that stretches from London via the Medway Towns to east Kent and (almost) to Dover. It doesn't even form the greatest part of that route, being just 25 miles of the 62-mile expressway. The rest is just the A2, but don't be fooled by the name: most of the widest and busiest parts are on the A2 sections, and the lengthy four-lane stretch that batters its way in an almost straight line from the M25 to the Medway is one of the widest and most impressive A-roads in the UK.

The purpose of the route is not to connect London and Dover, although it does do that - traffic between the two generally takes the M20 instead. The A2 and M2 are much more the route between London and the densely populated north coast of Kent, from Dartford to Gravesend to the Medway Towns to Thanet. At the eastern end of the M2, Brenley Corner, the motorway flows through an underpass directly into the A299 Thanet Way, the dual carriageway onward to Ramsgate and Margate, and the A2 connects to the motorway through a roundabout, highlighting the importance of north Kent over the road to Dover.

For a long time, the M2 was very much the junior party, a two-lane motorway that connected to a three-lane A-road. From the early 2000s, massive upgrade works to both the A2 and M2 have provided one of our most modern high-speed roads, a well-aligned four-lane route to Chatham and three lanes beyond there to Gillingham. Some of the M2's most notorious junctions, early examples of motorway design that had become dangerous and outdated, were also replaced. The works included the building of a second Medway Bridge parallel to the original and the wholesale realignment of several miles of A2.

So while the M2 may not be a long, important or significant motorway in its own right, when it's taken with its partner the A2 it's a force to be reckoned with.