The Cambridge line runs from Cambridge junction north of Hitchin on the East Coast Main Line to Shepreth Branch Junction south of Cambridge on the West Anglia Main Line and forms part of the route between London King's Cross and East Anglia. The line is part of the Network Rail Strategic Route 5, SRS 05.05 and is classified as a London and South East Commuter line. History Plans for a line between Hitchin and Royston were placed before Parliament in 1846 by the Royston and Hitchin Railway. The line was initially planned to be a single track spur from Hitchin, but during debate in the Lords it was recommended that the line be two track in the view of its possible later use as part of a route from to although this was later superseded by the Varsity line via . The line was opened in 1851 then extended to Cambridge by the Eastern Counties Railway although this was resisted by the company already operating a service from via the West Anglia Main Line. The line was then leased by the Great Northern Railway in 1850 and subsequently purchased in 1898 and through services run from to . In 2002, a train travelling from King's Cross to King's Lynn, via Cambridge, crashed at Potter's Bar, shortly before set to join the Cambridge line, killing seven. As part of the Great Northern Route electrification by British Rail in the mid 1970s, the through service was severed by the need to change from the electrified service at to a diesel train stopping at all stations to . The extension of electrification through to Cambridge was completed in 1988 under Network SouthEast and the track improved to increase speed. Occasional services are run by 12-car trains allowing them to stop only at Royston & Letchworth Garden City where the platform is long enough to accommodate them. The platform extension at Letchworth Garden City was completed in December 2011. The Down platforms at Shepreth and Foxton were extended in 2017 to allow 8-car trains to stop without blocking the level crossings. The flat junction at has always been an issue with conflicting train movements, but the Hitchin flyover to the north of the existing junction was opened in 2013 to carry north-bound services over the East Coast Main Line. Services Services on the line are run by both Thameslink and Great Northern as part