The A11 forms the main road from London to Norwich, and is the main road to the south for most of Norfolk and substantial parts of Suffolk and Cambridgeshire.
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.
Those last few miles of the M1 east of Leeds were completed in 1999. It looks for the most part like a fairly average piece of road, but one of the project's engineers describes some of the challenges that were faced.