text: Network Rail is doing work in the Chipping Sodbury and Alderton tunnels and building a new platform at Bristol Parkway.
  The improvements will run from Saturday until 15 September.
  They will allow new trains to run on the Great Western Rail mainline, including new intercity express trains.
  For the duration of the works, those travelling between south Wales and London should note:
  For those travelling to and from south Wales during the August Bank Holiday weekend from 26 August to 28 August:
  During the weekends from 23-24 September until 18-19 November, there will be further improvement work affecting south Wales and Bristol Parkway services.
  Passengers are advised to check their journeys.
target: Rail upgrade works affecting people travelling between south Wales, Bristol Parkway and London Paddington have begun.