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.
There's almost no evidence of Liverpool's 1960's plans for an inner ring road on the ground - but the motorway that never materialised would have been astonishing. The full details on the route, and the missing part the M62, are here.