Going round in circles: things you didn't know about the M25

1) It took more than two million tonnes of concrete and 3.5 million tonnes of black-top to cover the surface of the M25 alone and, if built today, it would cost the taxpayer 10 times as much as it did originally.

2) Before construction, the M25 route was subject to no fewer than 39 public inquiries, taking a total of 700 sitting days to complete.

3) Known as the nation's biggest car park, the M25 once experienced a 22-mile long traffic jam on the Surrey section in August 1988. The pop artist Chris Rea hated it so much that he wrote the song "Road to Hell" about it.

4) A company in Great Yarmouth has offered a grand coach tour of the M25 for the past 10 years and in 1992, 30 hotels gave bargain seven-day breaks on the motorway.

5) Almost everybody has missed an exit, including William Allen, a grandfather, 84 at the time, who spent two full days circling the M25 looking for his daughter's home.

6) The policemen patrolling the M25 are often witness to bizarre sights. A patrol car once encountered an elderly woman cycling in the opposite direction to the traffic, steering with one hand and holding her hat down against the slipstreams from the dodging vehicles with the other.

7) An AA patrol man, Carlton Avison, was fixing a vehicle on the hard shoulder of the M25 when a motorist stopped in the inside lane, asking him directions. In another incident a car was reported to have travelled at 70mph along the embankment, returning to the carriageway, amazingly hitting no other vehicles in the process.

8) The motorway even has its own mystery, when in July 1990 police discovered the mutilated body of a woman near South Mimms service station. The woman, still yet to be identified, lies in an unmarked grave, buried as "Jane Doe". Police have eliminated several possibilities but still want to identify her.

9) Who says that romance is dead? Chris and Sue Glazier, from Ashford, Kent, held their five-star wedding reception in a motorway service station. This was followed by a romantic night in a luxury coach, complete with honeymoon suite and destined to spend the evening circling the M25.