[T]hirty years ago a friend of mine took our son and his lad for a Sunday afternoon stroll and in the days when civil engineering was not carried out 24-hours a day, he decided, for reasons best known only by himself, to walk along the part constructed M25, thus making our son one of the few 10-year olds to have walked down the middle that motorway.

Our friend was of the opinion that this part constructed road, being so far out from central London, was a waste of money and would in all likelihood remain as empty as it was on the day they took their motorway ramble. It was I suppose his way of showing the future generation the folly of politicians with £1 billion of our money to spend.

Now I give you this illuminating if rather prosaic story of our family because on Saturday the motorway which inspired Chris Rea’s 1989 hit Road To Hell is 25-years-old, and our friend’s original prediction was soon proved wrong for less than two years after its opening by Margaret Thatcher on 17th August 1988 a 22-mile long queue of stationary traffic grew between junctions 9 and 10.

So here are CabbieBlog’s 25 fascinating facts after 25 years of the M25:

The construction was originally proposed in 1911, by the time Margaret Thatcher opened it in 1986 fourteen different Prime Ministers had been in office.

It runs for 117 miles (that is nearly 200 kilometres) and was the world’s biggest city ring road when it was built, now it is only surpassed by Berlin’s Ring at 121 miles.

For anyone who drove a car made in Britain at the time it will not come as a surprise to learn that the first breakdown on the M25 occurred at 11.16am on 29th October, 1986, just hours after Margaret Thatcher declared it open.

Head of the old Greater London Council and a leading lobbyist for the M25, Sir Horace Cutler, discovered to his dismay on the day the route was announced that it would pass through the grounds of his home near Gerrards Cross, Buckinghamshire.

The original design proposed four ring roads around London, but for political expedience in the 60s London County Council tried to keep quiet about their radical plans to build the four ring roads. The truth came out when Battersea Borough Council had a request for a new swimming pool rejected because one of the roads would have been built over it.

More than two million tons of concrete and 3.5 million tons of asphalt were used to build it and at junction 15 the M25 is now 12 lanes wide.

It has 10,606 lights and 2,959 illuminated signs along its length.

Clacket Lane Service Station is the largest service station in Europe, but despite its length and the volume of traffic the motorway has only two other service stations – Thurrock and South Mimms.

Designed with a capacity of 100,000 vehicles per day it now is used by 250,000 vehicles per day. At its busiest part 196,000 vehicles a day were measured in 2003 between junctions 13 and 14 near Heathrow Airport.

It has 33 junctions some of which are four levels high.

The highest speed recorded by police on the M25 was 147mph, in 1992 by Leslie Coe in a Porsche 911 – he lost his licence. Last year there were 793 accidents and eight deaths.

If you were able to drive at a constant 70mph, it would take an hour and 40 minutes to complete a full lap of the route.

One of the strangest items found on the motorway was a table tennis table amongst the tons or rubbish the Highways Agency maintenance crews have to clear off the hard shoulder each year.

According to the AA, the question most frequently asked by motorists on its online route planner is: “How can I avoid the M25?”

The Orbital road lent its name to a series of raves in the late eighties and early nineties. This in turn gave house duo Orbital their name.

Novelist Iain Sinclair walked anti-clockwise around the motorway in 2000 for his book “London Orbital”.

Explorers Alastair Humphreys and Rob Lilwall spent eight days walking the entire M25 route last year. Fans followed their progress via Twitter, with many locals offering beds for the night.

Last August Northern Irish fundraiser Trevor Sandford golfed his way around the motorway, covering 31 courses in 31 days, in aid of charity.

The tiny village of North Ockendon is the only settlement in Greater London outside the M25, while Watford (population 80,000) is the largest town outside Greater London to lie inside the M25.

Epping Foresters Cricket Club plays on a pitch directly above the M25’s Bell Common tunnel.

Since 1996 a man called Gimpo has spent a day each year driving around the M25. In fact, a day and a bit, as he takes 25 hours and he plans to do it until 2021. That’s a 25 year circumlocution spending 25 hours at a time on the M25. He calls it the M25 Spin, and it’s quietly becoming one of the most intriguing art projects out there.

If you drove round the M25 clockwise in the slow lane, you would travel 600ft further than if you drove round the motorway anti-clockwise in the slow lane.

The clockwise off-slip at Reigate is the longest slip-road in the world, outside of America.

Its north sections follow a similar route to the Outer London Defence Ring which was the defences built around the city for the Second World War.

And finally just in case you are reading this while stationary on the M25, a report this year revealed that roadworks had caused 118 years of hold-ups in 18 months between junctions 16 and 23 alone . . .