Editing M6 motorway (section)

===Planning and construction===
The first section of the motorway and the first motorway in the country was the [[Preston By-pass]]. It was built by [[Tarmac Group|Tarmac Construction]] and opened by the [[British Prime Minister|Prime Minister]] [[Harold Macmillan]] on 5 December 1958.<ref>{{cite web |url=http://www.cbrd.co.uk/histories/openingbooklets/pdf/prestonbypass.pdf |title=Preston Bypass Opening (Booklet) |access-date=20 January 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080229185452/http://www.cbrd.co.uk/histories/openingbooklets/pdf/prestonbypass.pdf |archive-date=29 February 2008}}</ref> In January 1959 the Preston by-pass was closed because of rapid surface deterioration over a stretch of {{convert|100|yd|m}} "due to water freezing and then thawing". Motorists were diverted to the old road while the UK road research laboratory at Harmondsworth pondered the importance of surface water drainage.<ref name="PracticalMotorist1959">{{cite magazine |title=The Preston By-pass-Enquiry Needed |magazine=Practical Motorist and Motor Cyclist |volume=5 |issue=57 |page=803 |date=March 1959}}</ref>

The second phase of construction was completed in 1960, forming the Lancaster by-pass. Some {{convert|100|mi|km}} south, the Stafford by-pass was completed in 1962.<ref name="Engineers1981"/><ref name="surveyor">{{cite book|title=Surveyor|edition=XII|series=1|volume=XII|year=1978|publisher=The St. Bride's Press|location=London|page=35|chapter=III}}</ref> By 1965, the remaining sections of motorway Stafford–Preston and Preston–Lancaster had been completed. 1966 saw junction 11 to 13 completed. 1968 saw the completion of the [[Walsall]] to Stafford link as well as the Penrith by-pass some {{convert|150|mi|km}} north in [[Cumberland]]. In 1970, the Lancaster–Penrith link was completed, along with a short section of motorway by-passing the south of Walsall. The most northerly section of the motorway also opened in 1970, running to the designated terminus north of Carlisle. By 1971 the full route was completed between the junction with the M1 motorway at Rugby and the [[A38 road]] several miles north-east of Birmingham city centre,<ref name="Engineers1981">{{cite book |title=The Highway Engineer |url={{GBurl|cPRVAAAAMAAJ}} |access-date=9 July 2012|year=1981 |publisher=Institution of Highway Engineers |page=23}}</ref> including [[Bromford Viaduct]] between [[Castle Bromwich]] (J5) and [[Gravelly Hill]] (J6), which at {{Convert|3.5|mi|km}} is the longest viaduct in Great Britain.<ref>{{cite web |url=http://www.ciht.org.uk/motorway/m5m6midlink.htm |title=Midland Links Motorways. M5 (J1 to J3) and M6 (J13 to J1) |publisher=[[Chartered Institution of Highways and Transportation]] |access-date=31 December 2011 |url-status=dead |archive-url=https://web.archive.org/web/20120207125434/http://www.ciht.org.uk/motorway/m5m6midlink.htm |archive-date=7 February 2012  }}</ref><ref name="(M.S.)2002">{{cite book |title=The Motorway Achievement – Frontiers of Knowledge and Practice |editor-first1=Ron |editor-last1=Bridle |editor-first2=John |editor-last2=Porter |url={{GBurl|7Yqxyefv-VAC|page=539}} |year=2002 |volume=2 |publisher=Thomas Telford |isbn=978-0-7277-3197-5 |pages=539–}}</ref>

Junction 6 in Birmingham, which opened in May 1972, is widely known as [[Gravelly Hill Interchange|Spaghetti Junction]] because of its complexity and round and curvy-like design. On the elevated ground between [[Shap]] and [[Tebay]], the north and south-bound carriages split apart.<ref name="Carpenter2011">{{cite book|first=T. G. |last=Carpenter|title=Construction in the Landscape: A Handbook for Civil Engineering to Conserve Global Land Resources |url={{GBurl|3vm90DLrfEYC|page=143}}|access-date=9 July 2012|date=27 January 2011|publisher=Routledge |isbn=978-1-84407-923-0 |pages=143–}}</ref> At this point a local road (to [[Scout Green]]) runs between the two carriageways without a link to the motorway.<ref name="The spectator">{{cite book|title=The Spectator |url={{GBurl|D24HAQAAIAAJ}}|access-date=9 July 2012|year=1980 |publisher=F. C. Westley |volume=245 |issue=2}}</ref>

The section of the M6 that runs over Shap Fell in Cumbria at [[Shap Summit]] is {{convert|1036|ft|abbr=on}} above sea level, one of the highest points on any motorway in the UK (Junction 22 of the [[M62 motorway|M62]] on Moss Moor is higher). The [[civil engineer|motorway engineers]] here chose to follow the route of the [[Lancaster and Carlisle Railway]] engineered by [[Joseph Locke]] (now part of the West Coast Main Line) where the motorway runs in a split-level cutting above the railway in the descent from Shap Fell through the Lune Gorge into southern Cumbria.<ref name="Government1965">{{citation |title=The Municipal Journal |volume=73 |year=1965 |publisher=Ministry of Housing and Local Government}}</ref>

The northbound entry slip road at Lancaster (Junction 34) was unusually short, presenting problems for traffic joining the motorway. The M6 crosses the [[River Lune]] at this point and unless the bridge had been made wider, there was no space to build a longer slip road. This junction was upgraded from an earlier emergency-vehicles-only access point, which explains the substandard design.<ref name="CommitteeCommons2005">{{cite book |author1=House of Commons: Transport Committee |title=Road Pricing: The Next Steps; Seventh Report of Session 2004–05 |date=2 August 2005 |publisher=The Stationery Office |isbn=978-0-215-02566-1 |pages=46–}}</ref> The construction of the [[Heysham to M6 Link Road]] (The Bay Gateway) has completely re-modelled this junction with a wide additional bridge over the River Lune and other works repositioning slip roads with new acceleration lanes to modern standards.

The route was originally intended to replace the old [[A6 road (England)|A6]], which it does along the northern section starting with the Preston Bypass. However, a much closer approximation to the overall actual route of the M6 (heading north from its southern terminus) is provided by following the [[A45 road|A45]], [[A34 road|A34]], [[A50 road|A50]], [[A49 road|A49]], then the [[A6 road (England)|A6]].<ref name="achievement2">{{cite book |title=The Motorway Achievement – The British Motorway System: Visualisation, Policy and Achievement |volume=1 |url={{GBurl|ndZVcax375EC|page=469}} |editor-first1=Peter |editor-last1=Baldwin |editor-first2=Robert |editor-last2=Baldwin |year=2004 |publisher=Thomas Telford |isbn=978-0-7277-3196-8 |pages=469–}}</ref> South of Preston, the A6 route is instead supplemented by the [[M61 motorway|M61]] as far as [[Manchester]], with the [[M60 motorway|M60]] acting as a bypass around the city. South of Manchester, there is no true motorway replacement for the old road. The [[M1 motorway|M1]] acts as a bypass for long-distance traffic in the south, from the [[Kegworth]] junction near [[Nottingham]], to [[Luton]] and [[St. Albans]] near London; but, it is not an alternative for local traffic as the routes diverge by more than {{Convert|15|mi|km}} while passing through [[Northamptonshire]]. Across the [[Pennines]], the old road remains the main local through-route, and long-distance fast traffic between [[Derby]] and Manchester must instead take either the [[A50 road|A50]] and M6, or M1 and M62.<ref name="motorway archive 1">{{cite web |url=http://www.ciht.org.uk/motorway/m5m6midlink.htm |title=M6 |work=The Motorway Archive. Midland Links Motorways |publisher=[[Chartered Institution of Highways and Transportation]] |access-date=9 July 2012|url-status=dead|archive-url=https://web.archive.org/web/20120207125434/http://www.ciht.org.uk/motorway/m5m6midlink.htm |archive-date=7 February 2012}}</ref>{{unreliable source?|date=July 2012}}

Once all sections of the motorway were constructed, and it was finally all linked together, the result was an uninterrupted motorway length of {{convert|230|mi}}.<ref name="Surveyor">{{cite book|title=Surveyor|year=1978|publisher=The St. Bride's Press|page=21}}</ref><ref name="ServicesInformation1970">{{cite book|author1=British Information Services|author2=Great Britain. Central Office of Information|title=Survey of British and Commonwealth affairs|url={{GBurl|8xIiAQAAIAAJ}}|access-date=9 July 2012|edition=I|series=One|volume=I|date=1 January 1970|publisher=Published for British Information Services by Her Majesty's Stationery Office|location=England, United Kingdom|chapter=I}}</ref><ref name="DivisionServices1979">{{cite book|author1=Central Office of Information |title=Inland transport in Britain|url={{GBurl|6EpnAAAAMAAJ}}|access-date=9 July 2012|year=1979|publisher=H.M.S.O.|isbn=978-0-11-700989-9}}</ref>