Officially named the London Orbital, nicknamed the 'Road to Hell', and frequently derided as nothing more than a very big car park, this is the world famous and rightly notorious M25.
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.
Speed limits are more emotive and divisive than almost anything else about the road network. How do you sort the fact from the opinion? And how did we end up with the speed limits we have?