Mark Langman, Network Rail route managing director for Wales, said there was 'potential for quicker and more frequent journeys on a network that is more resilient and reliable' in future.
He was speaking as the organisation set out plans for investing £1billion in the rail system.
This is an exciting time for the railway. We are now carrying a record number of people on record numbers of trains at record levels of reliability. This is an ambitious plan that will help move the railway in Wales to the next level.
More top news
Wales fans are continuing to celebrate yesterday's historic Euro 2016 win over Northern Ireland, which sees them make the quarter finals.
A lot has happened in the days since the Brexit result. We've been asking people how they're feeling about the fallout of the referendum.
Gareth Bale urged Wales to continue "riding the wave" after clinching their spot in the last eight of Euro 2016.