The M2 is the shortest of all the single digit motorways. It main role is to act as the Medway Towns Bypass. Originally allocated the number A2(M), it gained the M2 number from a newspaper report. The road opened in 1963.
The Medway Viaducts seen from the Merrals Shaw Interchange
Starting with Brenley Corner Interchange, most of the work was on the A299. It is due to making that road D2. However from the mid 1990's, the Western end of the motorway was upgraded to modern standards. Junction one was upgraded twice. Firstly the A289 from the Medway Tunnel was extended to here and the junction became a trumpet-fork hybrid. It became much busier. The second change was the replacement of the A2 bridge to D4M standard. The changes were much bigger at the Merrals Shaw Interchange. Here, HS1 was built though the junction so the original parclo slip roads were ripped up and the junction became a dumbbell hybrid. Also due to the building of the new Medway Viaducts, the Londonbound slips were also moved. Even the rebuilt Merrals Shaw Interchange is tame compared to the Bluebell Interchange. Here, the whole junction was wiped away (literally as the original overbridge on the M2 was blown up). Instead of being a trumpet hybrid, it became a double roundabout junction which is much bigger than the original junction. It has been rebuilt at least three times. This is mostly due to the A229 becoming dualled. After the Bluebell interchange, the road reverts to D3M before coming to junction 4 where the upgraded road ends. The only other change on the M2 is the renaming of its MSA from Farthing Corner to Medway services.
The M2 is one of the few motorways longer than 10 miles to fully appear on a single OS Landranger map (In this case map 178)