M25 Under Construction
The M25 under construction before it opened in 1986. (credit: Highways England, Open Government Licence)

The M25, as much a feature of England’s capital as Wembley’s arch, the London Eye or Tower Bridge, has reached the milestone of being operational for 30 years. 

Officially opened by Margaret Thatcher on October 29, 1986, the 117-mile stretch of road has catered to the needs of millions of commuters, holiday-goers and hauliers for three decades, allowing them to avoid the narrow and tricky to navigate streets of London. 

Spanning five counties – Kent, Surrey, Buckinghamshire, Hertfordshire and Essex – and encircling all of Greater London (with the exception of North Ockendon), it is Europe's second longest orbital road, coming in behind only the Berliner Ring, which is 122 miles long.

The motorway, as integral to the lives of millions of Britons as smartphones, HD television and internet shopping, and arguably as revolutionary as the UK’s rail network and the London Underground, has now been open for 10,958 consecutive days, and has for the vast majority of that time been required to cope with around twice the number of vehicles it was initially designed to deal with. 

Each day approximately 150,000 vehicles venture on to the M25, a number which far exceeds the 88,000 vehicles it was intended to tolerate when the road first opened. On particularly busy days the number of vehicles on the motorway has been known to swell to around 200,000 – almost two and a half times more than its original capacity.

M25 Now
The M25 now carries approx. 150,000 vehicles a day. (credit: Highways England, Open Government Licence)

Shell’s involvement

During its construction – which began in 1975 – more than two million tons of concrete and 3.5 million tons of asphalt were required to create the motorway. However, because the M25 has been in constant use for almost a third of a century, and owing to the fact that the number of vehicles using the road has increased dramatically since it was opened, maintenance has been a constant necessity.

David Whiteoak, former Technical Manager for Shell UK, spent much of his career working to develop modified bitumen solutions that would prolong the life not only of the M25, but numerous other roads around the UK.

He said: “The M25 is carrying far, far more vehicles than it was initially designed to cope with. While that’s the case for most roads in the UK, it’s especially true of the M25. And, because of this increased demand, Shell is constantly seeking to create advanced products that will keep roads in good condition.

“I remember one project that we carried out on the M25 with particular clarity. It was during the late ‘90s, and there was some maintenance work being carried out on Reigate Hill, which is a relatively steep section of road. The bitumen that was initially put down deteriorated rapidly – I’d say within a matter of weeks. Because this section of the motorway has a lot of HGV traffic travelling at low speed, the surface has to be incredibly robust or there will be a lot of damage and deformation.

“The solution was to re-surface the road with a polymer modified bitumen called Shell Cariphalte DM, a product developed by Shell specifically to improve the resilience of roads that are put under immense strain. This was an immediate success.

“This is just one example of Shell’s ongoing work to keep Britain moving. Maintaining and improving Britain’s roads may appear to be quite a straightforward task, but there is an incredible amount of intelligent work that goes into creating solutions that will stand the test of time.”

In popular culture

The road has provided inspiration for a number of authors, including Terry Pratchett, Neil Gaiman, and, perhaps most notably, Iain Sinclair, whose book London Orbital was written following a year-long journey around the M25 on foot.

Not only has the road stimulated the creative minds of a number of authors, but dance duo Orbital, who shot to prominence in the ‘90s, have credited the road as the inspiration behind their group’s name.

Did you know?

The M25 is the both the UK’s busiest and most recognisable motorway, but did you know the following?

  • The northern part of the M25 follows the route of the Outer London Defence Ring, set up at the beginning of World War Two
  • A ring road around London was first proposed in 1905 to make journeys via horse and cart subject to fewer delays
  • It would take approximately one hour and 40 minutes to circumnavigate the M25 while travelling at the national speed limit

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