page_title: M25 motorway
section_title: Route
hierarchical_section_title: M25 motorway / Description / Route
caption_attribution_description: English: The huge multi-level junction of the M23 (top) and M25 (bottom) near Merstham, Surrey
context_page_description: 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.
context_section_description: The M25 almost completely encircles Greater London and passes briefly through it to the east. Junctions 1A–5 are in Kent, 6–14 are in Surrey, 15–16 are in Buckinghamshire, 17–25 are in Hertfordshire, and 26–31 are in Essex. Policing of the road is carried out by an integrated group made up of the Metropolitan, Thames Valley, Essex, Kent, Hertfordshire and Surrey forces. Primary destinations signed ahead on the motorway include the Dartford Crossing, Sevenoaks, Gatwick Airport, Heathrow Airport, Watford, Stansted Airport and Brentwood.
  To the east of London the two ends of the M25 are joined to complete a loop by the non-motorway A282 Dartford Crossing of the River Thames between Thurrock and Dartford. The crossing consists of twin two-lane tunnels and the four-lane QE2 (Queen Elizabeth II) bridge. with a main span of 450 metres (1,480 ft). Passage across the bridge or through the tunnels is subject to a charge between 6 am and 10 pm, its level depending on the kind of vehicle. The road is not under motorway regulations so that other traffic can cross the Thames east of the Woolwich Ferry; the only crossing further to the east is a passenger ferry between Gravesend, Kent, and Tilbury, Essex.
  At Junction 5, the clockwise carriageway of the M25 is routed off the main north–south dual carriageway onto the main east–west dual carriageway with the main north–south carriageway becoming the A21.  In the opposite direction, to the east of the point where the M25 diverges from the main east–west carriageway, that carriageway becomes the M26 motorway. From here to Junction 8, the M25 follows the edge of the North Downs close to several historic buildings such as  Chevening, Titsey Place, Hever Castle and Chartwell. The interchange with the M23 motorway near Reigate is a four-level stack; one of only a few examples in Britain. Past this, the M25 runs close to the Surrey Hills AONB.
  To the west, the M25 passes close to the edge of Heathrow, and within sight of Windsor Castle. North of this, it crosses the Chiltern Main Line under the Chalfont Viaduct, a 19th-century railway bridge. Red kites can often be seen overhead to the north of this, up to Junction 21. The northern section of the M25 passes close to All Saints Pastoral Centre near London Colney, Waltham Abbey and Copped Hall. This section also features two cut-and-cover tunnels, including the Bell Common Tunnel. The north-eastern section of the motorway passes close to North Ockendon, the only settlement of Greater London situated outside the M25. It then runs close to the Rainham Marshes Nature Reserve before reaching the northern end of the Dartford Crossing.
  In 2004, following an opinion poll, the London Assembly proposed aligning the Greater London boundary with the M25. "Inside the M25" and "outside/beyond the M25" are colloquial, looser alternatives to "Greater London" sometimes used in haulage.  The Communications Act 2003 explicitly uses the M25 as the boundary in requiring a proportion of television programmes to be made outside the London area; it states a requirement of "a suitable proportion of the programmes made in the United Kingdom" to be made "in the United Kingdom outside the M25 area", defined in Section 362 as "the area the outer boundary of which is represented by the London Orbital Motorway (M25)".
  Sections of the M25 form part of two long-distance E-roads, designated by the United Nations Economic Commission for Europe. The E15, which runs from Inverness to Algeciras, follows the M25 and A282 clockwise from the A1(M) at junction 23 to the M20 at junction 3; while the E30 Cork to Omsk route runs from the M4 at junction 15, clockwise to the A12 at junction 28. The United Kingdom is formally part of the E-roads network but, unlike in other countries, these routes are not marked on any road signs.
caption: Four-level stack where the M25 meets the M23
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