Editing Northern line (section)

====Progress of works====
Work began in the late 1930s and was in progress on all fronts by the outbreak of the [[World War II|Second World War]]. The tunnelling northwards from the original Highgate station (now [[Archway tube station|Archway]]) had been completed, and the service to the rebuilt surface station at [[East Finchley tube station|East Finchley]] started on 3 July 1939 but without the opening of the intermediate (new) Highgate Station at the site of the LNER's station of the same name. Further progress was disrupted by the start of the war; however enough development had been made to complete the electrification of the [[High Barnet tube station|High Barnet]] branch onwards from East Finchley (over which tube services started on 14 April 1940) and the new deep-level [[Highgate tube station|Highgate]] station opened on 19 January 1941. The single track LNER line to Edgware was electrified as far as [[Mill Hill East tube station|Mill Hill East]], including the [[Dollis Brook Viaduct]], opening as a tube service on 18 May 1941 to serve the barracks there thus forming the Northern line as it is today. The new depot at Aldenham had already been built and was used to build [[Handley Page Halifax|Halifax]] bombers. Work on the other elements of the plan was suspended late in 1939.

Work on the extension from Edgware to Bushey Heath including work on a viaduct and a tunnel started in June 1939, but was stopped after war broke out.{{sfn|Beard|2002|pp=90–92}} After the war, the area beyond Edgware was made part of the [[Metropolitan Green Belt]], largely preventing the anticipated residential development in the area, and the potential demand for services from Bushey Heath thus vanished. Passenger numbers also dropped on the then-[[British Rail|BR]]'s Mill Hill and Alexandra Palace branches, so it was useless to electrify them. Available funds were directed towards completing the eastern extension of the [[Central line (London Underground)|Central line]] instead, and the Northern Heights plan was dropped on 9 February 1954. Aldenham depot was converted into an overhaul facility for buses.

The implemented service from High Barnet branch gave good access both to the [[West End of London|West End]] and the [[City of London|City]]. This appears to have undermined traffic on the Alexandra Palace branch, still run with steam haulage to [[King's Cross St Pancras tube station|Kings Cross]] via Finsbury Park, as Highgate (low-level) was but a short bus ride away and car traffic was much lighter than it would become later. Consequently, the line from Finsbury Park to Muswell Hill and Alexandra Palace via the surface platforms at Highgate was closed altogether to passenger traffic in 1954.{{citation needed|date=May 2020}} This contrasts with the decision to electrify the Epping-Ongar branch of the Central line, another remnant of the New Works programme, run as a tube-train shuttle from 1957. A local pressure group, the Muswell Hill Metro Group, campaigns to reopen this route as a light-rail service.{{citation needed|date=May 2020}} So far there is no sign of movement on this issue: the route, now the [[Parkland Walk]], is highly valued by walkers and cyclists, and suggestions in the 1990s that it could, in part, become a road were met with fierce opposition.{{citation needed|date=May 2020}} Another pressure group has proposed using the track bed further north, as part of the [[North and West London Light Railway]].{{citation needed|date=May 2020}} The connection between [[Drayton Park railway station|Drayton Park]] and the surface platforms at Finsbury Park was opened in 1976, when the Northern City Line became part of [[British Rail]].