The longest ring road in the world, the M25 was designed to make traffic drive around London instead of through it. A brilliant plan - except that there really isn't enough space for all the traffic that wants to do this.

HISTORY / FASCINATING FACTS /
ANORAK SPOT / JOKES

Brief history
The planning and construction of ring roads around London began in 1911 following recommendations of the 1905 Royal Commission on London Traffic.

But official road planning had usually treated it as two roads - the North and South Orbitals - rather than a complete ring.

The A10 tunnel - Herts

Construction of what we now know as the M25 had officially started in March 1957 with the Dartford Tunnel North Approach.

But up until 1975, it was still very much two roads, north and south, with the M16 outer orbital in the north and the M25 in Kent and Surrey in the south.

In November 1975 the Minister of Transport, John Gilbert, announced that these would be subsumed into a single ring - the London Orbital Motorway (M25).

Its construction appears to have been rather haphazard. It is true that it was developed in a rather piecemeal fashion, but this is because each length had to be proposed by law and then justified on its own merits.

Individual sections were completed according to the problems encountered in passing through these statutory procedures.

The final piece of the motorway, Micklefield to South Mimms (J19 to J23), was opened to traffic in October 1986.

Fascinating facts (yes they are!)

• It is 195.5 km (121.5 miles) long.

• It cost an estimated £909m to build (£7.5m per mile).

• It does not completely encircle London as the eastern crossing at Dartford is formed of the A282 which is a general purpose road partly in Kent and partly in Essex linked by the Dartford tunnel and bridge which are tolled highways.

• Between junctions 15 and 14 (M4 to A3113) the M25 carries 165000 vehicles per day* making it the busiest motorway in the UK.

• On the 17 August, 1988, there was 22 miles of stationary traffic between junctions 9 and 8.

• There were 39 public inquiries before independent Inspectors were held, taking over 700 sitting days.

• A special Act was needed to authorise the crossing of the northern tip of Epping Forest.

• There are 31 junctions (32, if Junction 21A is counted separately) numbered from Junction 1 south of the Dartford Tunnel clockwise round to Junction 31 north of Dartford Tunnel connecting with A13.

• These interchanges include nine major motorway-to-motorway interchanges.

• The signing system on the M25 uses five key destinations - Heathrow, Gatwick, Dartford Tunnel, Harlow and Watford. At the approaches to the M25 the signs show the next key destination. The idea of this is to help drivers go the right way round it.

• An average of 20,000 trees per mile have been planted alongside and near the carriageways.

• Four service stations were originally planned. At the moment there are only three, Clacket Lane between Junction 5 and 6, South Mimms at Junction 23 and Thurrock between Junction 30 and 31. The fourth proposed site was at Iver on the five mile length between Junction 15 and 16.
  

• When it's quiet you can stay on it for hours and still end up in the same place.

• When it's busy you can stay on it for hours and still end up in the same place.

• In the year 2000 novelist, poet and "psychogeographer" Iain Sinclair walked anti-clockwise around the motorway for his book London Orbital.

• Along with the Great Wall of China, it is supposedly one of the few man-made constructions that is visible from space.

• It's a metaphor for life, if you drive along it for long enough, you return to your starting point.
  

*1997 Guiness Book of Records which is the only copy we could find!

Anorak spot
Look here for full details of the construction dates for each section of the M25.

Look at The Motorway Archive for details of every section, tunnel, bridge and more ....

Jokes

Nutcase
A woman was watching the six o'clock news at home, when she heard on it that there was a car driving down the wrong side of the M25.

She realised that her husband would probably be driving home from work along the M25, so she rang him up on his mobile, and said "Be careful darling, some nutcase is driving along the M25 on the wrong side", to which he replied "tell me about it, there're hundreds of them at it."

Don't drink
The M25 walked into a bar and said: "I'm really hard give me a vodka."

He drank this really quickly, and said again: "I'm really hard give me another vodka." Just then red tarmac walked into the bar and the M25 ran and hid.

A few minutes later when the red tarmac had gone out the M25 came out. The barman said : "You were saying the you were really hard but when red tarmac came in you hid." The M25 replied: "He's a cycle path!"