There will be no trains running between Bristol Parkway and Newport over the Easter weekend while electrification work takes place in the Severn Tunnel.
From Good Friday to Easter Monday replacement buses will operate between the stations for trains between South Wales and London Paddington.
Trains from Portsmouth to Cardiff will also terminate at Bristol Parkway and trains from Taunton will terminate at Bristol Temple Meads.
This is when the buses will be running in and around Bristol over the Easter weekend
Great Western Railway has said journeys would be quicker when the work was finished.
A Network Rail spokesperson said: “Trains are now running under electric power between London Paddington and Bristol Parkway, following the completion of overhead line equipment between Swindon and Bristol Parkway in December 2018.
“We now plan to complete the section between Bristol Parkway and Cardiff by the end of 2019.
“In the South Gloucestershire area, we need to install the remaining overhead wires between Bristol Parkway and the Severn Tunnel, and we also need to carry out further work, including track drainage, within the Patchway Tunnels.”
Patchway train station to close over Easter weekend for lift and bridge work
Further work is also planned for the weekend of April 27 and 28 when trains between London Paddington and south Wales will be diverted via other routes.
