Improved signalling, station improvements and faster trains are among the measures planned by Network Rail. Work to electrify the line between the Severn Tunnel and Swansea should be complete by December 2018, paving the way for bigger, faster and more environmentally-friendly electric trains.
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Fire crews have been responding to reports of flash flooding in Carmarthenshire. Some homes have been affected.
Medication designed for animals was taken from the building in Abertillery on Thursday night.
More than a thousand riders will be taking part in a series of events in and around the town.