Swindon to Kemble Easter works will impact rail passengers
Rail passengers have been told to expect disruption throughout April as work continues on a line between Gloucestershire and Wiltshire.
First Great Western (FGW) said the "less busy" Easter period was being used for further ground preparation works between Swindon and Kemble.
Some timetables will be altered and replacement bus services will be in operation during the holiday period.
FGW customers will be able to use their tickets with other rail operators.
The second track is expected to be laid during August which will allow four trains per hour to travel on the line in each direction.