Between them, the M50, A40 and A449 form a single dual carriageway route connecting the West Midlands to South Wales, incorproating one of the UK's oldest and most scenic motorways.
It was the UK's only single-carriageway motorway, and twenty years ago it ceased to exist. This is the story of the strange fascination it held, and of my place in history.
The UK's first four-level interchange opened in 1966. Relive some of the wonder and excitement of this icon of the motorway era with the book published to mark its completion.