It follows a campaign by commuters for a later rush hour service in the evening to help ease overcrowding.
Other Thames Valley services will have more carriages with first class compartments converted for use by standard ticket holders. There are also extra trains between Swindon and Westbury.
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Manali has Friday morning's forecast for the west of the Meridian region.
Manali has Friday morning's forecast for the east of the Meridian region.
The schools attended by two teenagers killed with their parents when their seaplane crashed in Canada have paid tribute to the pair.