Reading–Taunton line marketed as the "Kennet Line", follows the River Kennet through the outer suburbs of Reading to Theale. The line passes through Berkshire countryside and local stations at Aldermaston, Midgham and Thatcham. Newbury race course lies alongside the line on the left and has its own station a short distance east of the main Newbury railway station, where the town centre is close by on the right of the line. The station has a bay platform on the right for local terminating trains, and the through platforms are on loop lines that allow fast trains to overtake the local services that
Reading–Taunton line to Taunton line entirely. A few services from London travel only part way along the line, terminating at Westbury or Frome. GWR also provide local services along parts of the line, between Reading and Bedwyn, and between Westbury and Castle Cary. The route is double-track throughout, with passing loops at certain locations. The highest line-speed on the route is . The route has a loading gauge clearance of W7 except Reading to Westbury and Taunton to Exeter, which are the larger W8, and is open to rolling stock up to Route Availability 8. Signalling requires four minutes between trains on