Editing M25 motorway (section)

===Construction===
[[File:M25 - Work In Progress at Tatling End - geograph.org.uk - 37213.jpg|thumb|View north from Higher [[Denham, Buckinghamshire|Denham]] Fire Station at Tatling End on the A40 in July 1984, with the [[Chiltern Main Line]] five-arch 1906 [[Chalfont Viaduct]], originally built to straddle the [[River Misbourne]] ]]
There was no individual [[public inquiry]] into the M25 as a whole.{{sfn|Asher|2018|p=116}} Each section was presented to planning authorities in its own right and was individually justified, with 39 separate public inquiries relating to sections of the route. The need for the ministry to negotiate with local councils meant that more junctions with local traffic were built than originally proposed.{{sfn|Asher|2018|p=117}} A report in 1981 showed that the M25 had the potential to attract office and retail development along its route, negating the proposed traffic improvements and making Central London a less desirable place to work.{{sfn|Asher|2018|p=118}} None of the motorway was prevented from being built by objections at the public inquiries.{{sfn|Hamilton|2015|p=11}} However, as a consequence of the backlash against the Ringways, and criticism at the public inquiries, the motorway was built with environmental concerns in mind. New features included additional earth mounds, cuttings and fences that reduced noise, and over two million trees and shrubs to hide the view of the road.{{sfn|Moran|2009|pp=208–209}}

[[File:Progress on M25 motorway, south of Cobham - geograph.org.uk - 6442228.jpg|thumb|right|South of Cobham in October 1983]]
Construction of parts of the two outer ring roads, Ringways 3 and 4, began in 1973. The first section, between South Mimms and Potters Bar in Hertfordshire (junctions 23 to 24) opened in September 1975.{{sfn|Asher|2018|p=115}}<ref name="tmad">{{cite web|title=M25 : London Orbital Motorway – Dates|url=http://www.ukmotorwayarchive.org.uk/en/motorways/motorway-listing/m25-london-orbital-motorway/dates.cfm|archive-url=https://web.archive.org/web/20200803151154/http://www.ukmotorwayarchive.org.uk/en/motorways/motorway-listing/m25-london-orbital-motorway/dates.cfm|archive-date=3 August 2020|work=UK Motorway Archive}}</ref> It was provisionally known as the M16 and was given the temporary general-purpose road designation [[A1178 road|A1178]].<ref>{{cite news|url=https://www.independent.co.uk/travel/news-and-advice/simon-calder-how-london-got-its-ring-road-2088171.html|title=How London got its Ring Road|first=Simon|last=Calder|newspaper=The Independent|date=25 September 2010|access-date=11 May 2019}}</ref> A section of the North Orbital Road between [[Rickmansworth]] and [[Hunton Bridge]] was proposed in 1966, with detailed planning in 1971. The North Orbital Extension was given the go-ahead in January 1973, from Maple Cross. It was 6.2 miles, and was to cost £6.5m.<ref>''Buckinghamshire Examiner'' Friday 26 January 1973, page 1</ref> The road was constructed to motorway standards and opened on Thursday 26 February 1976, as a section of the [[A405 road|A405]].<ref>''Birmingham Daily Post'' Thursday 26 February 1976, page 25</ref><ref>{{London Gazette | issue = 47053 | date = 28 October 1976 | pages = 14527-14528}}</ref> It eventually became part of the M25's route.{{sfn|Asher|2018|p=115}}<ref name=tmad/> The section to the south, from [[Heathrow Airport]] to Rickmansworth had five separate routes proposed when a public inquiry was launched in 1974. The Department of Transport sent out 15,000 questionnaires about the preferred route, with 5,000 replies. A route was fixed in 1978, with objections delaying the start of construction in 1982.{{sfn|Hamilton|2015|p=11}}

[[File:Progress on M25 motorway, south of Cobham - geograph.org.uk - 6442227.jpg|thumb|right|Construction in October 1983]]
The southern section of what became the M25 through Surrey and Kent was first conceived to be an east–west road south of London to relieve the [[A25 road|A25]], and running parallel to it, with its eastern end following the route of what is now the [[M26 motorway|M26]]. It was originally proposed as an all-purpose route, but was upgraded to motorway standard in 1966. It was the first section of the route announced as M25 from the beginning. The first section from [[Godstone]] to [[Reigate]] (junctions 6 to 8) was first planned in 1966 and opened in February 1976.{{sfn|Asher|2018|p=115}}<ref name=tmad/> A section of Ringway 3 south of the river between Dartford and Swanley (junctions 1 to 3) was constructed between May 1974 and April 1977.<ref name=tmad/>

[[File:Bell Common Tunnel - geograph.org.uk - 53233.jpg|thumb|left|Inside the [[bell Common#Tunnel|Bell Common Tunnel]] near [[Epping, Essex|Epping]]]]
In 1975, following extensive opposition to some parts of Ringway 3 through Middlesex and South London, the transport minister [[John Gilbert, Baron Gilbert|John Gilbert]] announced that the north section of Ringway 3 already planned would be combined with the southern section of Ringway 4, forming a single orbital motorway to be known as the M25, and the M16 designation was dropped. This scheme required two additional sections to join what were two different schemes, from Swanley to Sevenoaks in the south-east and Hunton Bridge to Potters Bar in the north-west. The section of Ringway 3 west of South Mimms anti-clockwise around London to Swanley in Kent was cancelled.{{sfn|Asher|2018|p=116}}

The section from Potters Bar to the [[Dartford Tunnel]] was constructed in stages from June 1979 onwards, with the final section between [[Waltham Cross]] (junction 25) to [[Theydon Garnon]] (junction 27) opening in January 1984.<ref name=tmad/> This section, running through [[Epping Forest]], attracted opposition and protests. In 1973, local residents had parked [[combine harvester]]s in [[Parliament Square]] in protest against the road, draped with large banners reading "Not Epping Likely". As a consequence of this, the [[Bell Common Tunnel]] that runs in this area is twice as long as originally proposed.{{sfn|Asher|2018|p=119}}

The most controversial section of the M25 was that between Swanley and Sevenoaks (junctions 3 to 5) in Kent across the [[Darenth|Darenth Valley]], [[Badgers Mount]] and the [[North Downs]]. An 1,800-member group named Defend Darenth Valley and the North Downs Action Group (DANDAG) argued that the link was unnecessary, it would damage an [[Area of Outstanding Natural Beauty]] and it would be primarily used by local traffic as a bypass for the old [[A21 road (England)|A21 road]] between Farnborough and Sevenoaks.{{sfn|Asher|2018|p=121}} After a length inquiry process, chaired by [[George Dobry]] [[Queen's Counsel|QC]], the transport minister [[Kenneth Clarke]] announced the motorway would be built as proposed.{{sfn|Asher|2018|p=120}}

The section from the [[M40 motorway]] to the 1970s North Orbital Road construction (junctions 16 to 17) opened in January 1985.{{sfn|Asher|2018|p=121}} The route under the [[Chalfont Viaduct]] meant the motorway was restricted to a width of three lanes in each direction.<ref>{{cite news|url=https://www.telegraph.co.uk/travel/destinations/europe/united-kingdom/galleries/M25-The-best-of-Britains-most-hated-motorway/m25-summary/ |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/travel/destinations/europe/united-kingdom/galleries/M25-The-best-of-Britains-most-hated-motorway/m25-summary/ |archive-date=12 January 2022 |url-access=subscription |url-status=live|title=M25: The best of Britain's most hated motorway|newspaper=The Daily Telegraph|access-date=11 May 2019}}{{cbignore}}</ref>

The [[Prime Minister of the United Kingdom|Prime Minister]], [[Margaret Thatcher]], officially opened the M25 on 29 October 1986, with a ceremony in the section between junctions 22 to 23 ([[London Colney]] and [[South Mimms]]).<ref name=independent_20161017>{{cite news|url=https://www.independent.co.uk/life-style/motoring/features/the-m25-were-on-the-road-to-nowhere-420365.html|title=The M25 : We're on the road to nowhere|newspaper=The Independent|date=17 October 2006|access-date=11 May 2019}}</ref> To avoid the threat of road protesters, the ceremony was held a quarter of a mile from the nearest bridge.{{sfn|Moran|2009|p=209}} The total estimated cost of the motorway was around £1{{nbsp}}billion. It required {{convert|2|e6tonne|e6ST|abbr=off}} of concrete, {{convert|2.5|e6tonne|e6ST|abbr=off}} of [[Asphalt concrete|asphalt]] and involved the removal of {{convert|49|e6m3|e6cuft|abbr=off}} of spoil. Upon completion, it was the longest orbital motorway in the world at {{convert|117|miles}}.{{sfn|Asher|2018|p=121}}{{efn|name=Berliner_Ring_is_longer}} At the opening ceremony, Thatcher announced that {{convert|98|mi}} had been constructed while the [[Conservative Party (UK)|Conservative Party]] were in office, calling it "a splendid achievement for Britain".{{sfn|Moran|2009|p=209}} A 58-page brochure was published, commemorating the completion of the motorway.{{sfn|Hamilton|2015|p=14}}