The Hertford loop line is a branch of the East Coast Main Line, part of the Northern City Line commuter route to London for Hertford and other Hertfordshire towns and an occasional diversion route for the main line. The line is part of the Network Rail Strategic Route 8, SRS 08.03 and is classified as a London and South East Commuter line.

Stevenage railway station serves the town of Stevenage in Hertfordshire, England. The station is around 44.4 kilometres north of London King's Cross on the East Coast Main Line. Stevenage is served and managed by Great Northern, who operate Thameslink stopping services southbound to King’s Cross via stations such as Welwyn Garden City and Potters Bar, to Brighton and Horsham via central London and Gatwick Airport and to Moorgate via Watton-at-Stone, Hertford North and Enfield Chase and services northbound to Cambridge and Peterborough. It is also frequently served by London North Eastern Railway, who operate fast non-stopping services southbound towards London and northbound towards cities including York, Leeds and Edinburgh. Hull Trains and Lumo operate very limited services from the station.