Network Rail is investing £750 million to improve train services between London Paddington and the West Country and South Wales over the next three years.  This will include the replacement of hundreds of miles of track. 

The junction at Wootton Bassett, where the route splits to Bristol Temple Meads and to Bristol Parkway west ofSwindon, will be one of the first parts of the route to benefit from the investment.

This important work sees the route closed between Swindon and Bristol Temple Meads and between Swindon and Bristol Parkway from 01.25 on Saturday 26 August until 05.30 Monday 4 September 2006.

The work at Wootton Bassett Junction as well as Chipping Sodbury and Rushey Platt is one of the largest undertaken on the Great Western route in many years and consists 21 new points being installed and 1,800m of plain track. With the exception of the High Output Ballast Train working in the Christian Malford area which will be powered by Freightliner Heavy Haul, all ballast trains will be operated by EWS, during the period of closure 30 engineering trains are expected to be involved. In case of main line problems a Class 67 will be stationed at Bristol Barton Hill on 'Thunderbird' duties which will have an HST coupler available to clear the line in case of failure.

Train services will be diverted via alternative routes adding extra time to journeys and buses will run between a number of stations to meet connections to South Wales, Bristol, Gloucester and Cheltenham, Thames Valley and London Paddington.

London/South Wales services - There will be a limited peak-time direct train service between Bristol Parkway and London Paddington diverted on an alternative route. An hourly service in both directions diverted via Gloucester to Swindon not calling at Bristol Parkway but some calling additionally at Stonehouse, Stroud and Kemble. A bus link will run between Bristol Parkway and Swindon for train connections to and from London Paddington. A bus service will also run between Bristol Parkway and Filton Abbey Wood for connections to and from South Wales.
London/Bristol services - These services will be diverted between Bath Spa and Reading and will not call at Chippenham, Swindon or Didcot. A train shuttle service will also run between Bristol Temple Meads and Chippenham calling at Bath Spa, with a bus link between Chippenham and Swindon to connect into train services to London Paddington. A limited peak-time train service will run between Chippenham and London Paddington which will operate on an alternative route through to Reading.
London/Cheltenham Spa services - These services will be re-timed to incorporate the diverted South Wales services.
Swindon/Didcot Parkway – These stations will be served by a regular Swindon to London Paddington train service and by diverted South Wales services.
Swindon/Southampton services – A replacement bus service will run between Westbury and Swindon. Train services will run between Westbury and Southampton.