The Medway Motorway, or Medway Towns Bypass, was opened in around 1965 as a handy way to get past Chatham, Gillingham and Rochester. The whole of the M2 was pretty much one big project, and these two booklets commemorate the opening of the road itself and the Medway Bridge, its major engineering feature.
The motorway's western end was upgraded out of all recognition from these documents in the early 2000s, and the Medway Bridge itself was duplicated with a near-identical copy to widen the motorway.
Further reading on the Medway Bridge.