M25 motorway

The M25 or London Orbital Motorway is a major road encircling almost all of Greater London, England. The Dartford Crossing is part of the orbital route but is not part of the motorway. The M25 is one of the most important roads in Britain and one of the busiest. The final section was opened by the Prime Minister Margaret Thatcher in 1986; on opening it was the longest ring road in Europe at 117 miles .

Patrick Abercrombie had proposed an orbital motorway around London in the 1944 Greater London Plan, which evolved into the London Ringways project in the early 1960s. By 1966, planning had started on two projects, Ringway 3 to the north and Ringway 4 to the south. By the time the first sections opened in 1975, it was decided the ringways would be combined into a single orbital motorway. The M25 was one of the first motorway projects to consider environmental concerns and almost 40 public inquiries took place. The road was built as planned despite some protest that included the section over the North Downs and around Epping Forest which required an extension of the Bell Common Tunnel.

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