Railtrack was the former operator and owner of the majority of the railway infrastructure in Great Britain. Following a brief period in administration, the company was taken over by state-owned Network Rail in 2002.
| Current franchises|
Chiltern | East Anglia (Stansted Express) | East Midlands | Essex Thameside | Greater Western | InterCity East Coast | InterCity West Coast | Merseyrail | New Cross Country | Northern | ScotRail | South Eastern | South Western (Island Line) | Thameslink, Southern and Great Northern (Gatwick Express) | TransPennine | Wales and Borders | West Midlands
Defunct British Rail sectors