The station is on an east–west alignment, with the main station building and car park to the north of the line. There are six lines through the station, of which the inner four have platforms, the outer two being goods loops. There is a goods yard adjacent to the station to the south. The station has four platforms, numbered 1 to 4 from south to north. Platforms 1 and 2 share an island to the south of the two central lines, platform 1 is on the south side of the island and serves southbound trains towards Bristol Temple Meads, platform 2 is on the north side of the island and serves westbound trains towards Wales and Bristol Temple Meads. Platforms 3 and 4 share an island to the north of the two central running lines. Platform 3 serves mainly inter-city trains towards London and , while platform 4 is usually reserved for local services. An enclosed footbridge provides access to the platforms, approximately a third of the way along platforms 2 and 3 (from west to east), and at the west end of platforms 1 and 4. Platforms 2 and 3 are opposite each other, while platforms 1 and 4 are offset from platform 3, starting at the footbridge and extending further to the east. All platforms are long. Platforms 1, 3 and 4 are signalled for bidirectional running, while platform 2 is unidirectional. The footbridge can be accessed by both stairs and lifts.