Passengers travelling between London and South Wales are being urged to plan ahead this summer as essential engineering work affects services between Swindon and Bristol Parkway. From 6 July to 2 August, and again on 8-9 August, trains will run hourly instead of more frequently, with journeys between London Paddington and South Wales taking around 25 minutes longer due to diversions. Some stopping patterns will also change, while extra services will operate between London Paddington and Swindon. No rail replacement buses are planned. Network Rail is replacing track, carrying out structural work in Chipping Sodbury Tunnel and renewing track west of Swindon to improve reliability and make the railway more resilient to extreme weather. Passengers are advised to check before travelling, allow extra time and reserve seats where possible. https://news.gwr.com/news/travel-between-london-and-south-wales-what-customers-need-to-know-during-summer-rail-upgrades