The InterCity 225 is an electric push-pull high speed train in the United Kingdom, comprising a Class 91 electric locomotive, nine Mark 4 coaches and a Driving Van Trailer (DVT). The Class 91 locomotives were built by British Rail Engineering Limited's Crewe Works as a spin-off from the Advanced Passenger Train project, which was abandoned during the 1980s, whilst the coaches and DVT were constructed by Metro-Cammell in Birmingham and Breda in Italy, again borrowing heavily from the Advanced Passenger Train. The trains were designed to operate at up to 140 mph (225 km/h) in regular service, but are limited to 125 mph (200 km/h) principally due to a lack of cab signalling and the limitations of the current overhead line equipment. They were introduced into service between 1989 and 1991 for intercity services on the East Coast Main Line (ECML) from London King's Cross to Leeds, York and Edinburgh.

The InterCity 125 or High Speed Train (HST) is a diesel-powered high-speed passenger train built by British Rail Engineering Limited between 1975 and 1982. A total of 95 sets were produced, each comprising two Class 43 power cars, one at each end, and a rake of seven or eight Mark 3 coaches. The name is derived from its top operational speed of 125 mph (201 km/h). At times, the sets have been classified as British Rail Classes 253, 254 and 255.