Rail passengers travelling from Bristol Parkway are being warned of major disruption over the next three weeks.
The station will be closed to trains for engineering work linked to electrification - with services diverted via Bristol Temple Meads.
From Saturday 15 September to 6 October, bus replacement services will run between Bristol Parkway, Temple Meads, Yate, Swindon and Newport.
HOW WILL MY JOURNEY BE AFFECTED?
Between London Paddington and South Wales, trains will be diverted between Swindon and Newport – calling at Patchway instead of Bristol Parkway.
Between Cardiff Central and Portsmouth Harbour or Taunton, trains will continue to run but to a slightly amended timetable.
From Great Malvern, Worcester Shrub Hill or Gloucester towards Bristol Temple Meads, trains will terminate at Yate – connecting coaches will run from Yate, via Bristol Parkway, to Filton Abbey Wood for trains towards Bristol Temple Meads.
From Westbury or Weymouth towards Bristol Parkway, trains will terminate at Filton Abbey Wood – connecting coaches will run from Filton Abbey Wood, via Bristol Parkway, to Yate for trains towards Gloucester and the North Cotswolds.
From Weston-super-Mare or Taunton to Bristol Parkway, trains will terminate at Bristol Temple Meads – trains will run from Bristol Temple Meads to Filton Abbey Wood for connecting coaches to Bristol Parkway.
CrossCountry trains will be diverted between Cheltenham Spa and Bristol Temple Meads – calling at Patchway instead of Bristol Parkway
Network Rail said work on the city's rail lines will help "reduce congestion, cut journey times, increase capacity and improve reliability".
REPLACEMENT BUS SERVICE TIMES:
Bristol Parkway to Patchway - Every 30 minutes
Bristol Parkway to Filton Abbey Wood - Hourly
Filton Abbey Wood to Yate - Hourly
Services will also be affected on:
13 to 14 October
27 October to 18 November
24 to 25 November
1 to 2 December
There are more travel details at: GWR.com/Check.