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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Wales have qualified for the Euro 2016 quarter finals after beating Northern Ireland 1-0 in Paris.
A rally has been held in Cardiff following the EU referendum to show support to migrant communities.
It's 0-0 at half time in Paris as Wales face Northern Ireland in the last 16 of Euro 2016.