Latest figures from Network Rail show Arriva Trains Wales achieved an annual "Right Time" average of 82.8 per cent in 2017.
The figures, which show the percentage of trains reaching their destination within 59 seconds of the advertised time, are compiled by Network Rail every four weeks.
Achieving as reliable service as possible for customers has always been a key aim for Arriva Trains Wales.
In 2016, Arriva Trains Wales delivered 259,812 right time services. However in 2017 we delivered 272,926, an increase of five per cent.
“We’re delighted to finish the year as the best right time operator in the UK which is thanks to the tireless efforts of our people and those of our close partners in Network Rail," said Arriva Trains Wales Managing Director Tom Joyner.
“Customers and communities are at the heart of the service we provide in Wales and the borders, so to give them as efficient and reliable a service as possible is an absolute priority.
“This year has seen a lot of challenges and changes for Wales, from being battered by multiple storms to hosting one of the biggest sporting events in the world, with the UEFA Champions League Final coming to Cardiff.
"Our engineers are real heroes too, with the age of our rolling stock being a constant challenge for them in order to maintain our comparatively high standards of punctuality.
"There has been some major investment in infrastructure by Network Rail including the £300 million CASR project.
“We also saw a major timetable change in May, helping us run more services daily than ever before.
“But despite these challenges and changes we’ve delivered consistently good right time performance throughout the year compared to the rest of the UK rail industry and there is a lot more to come in 2018."
Punctuality is currently measured on the "Public Performance Measure" (PPM) and "Right Time".
PPM measures arrival at a trains destination within five minutes of the advertised time for shorter journeys or 10 minutes for longer distance ones. On this measure, Arriva Trains Wales finished the year in a credible 7th best position with a 92.4 per cent average for the year. Right Time means reaching the final destination within 59 seconds of the advertised time.
Andy Thomas, route managing director for Network Rail in Wales and Borders, said: "We are delighted to have supported Arriva Trains Wales in being the best ‘Right Time’ train operator in 2017. Enhancements completed last year as part of our Railway Upgrade Plan –such as the major improvement to signalling equipment in Cardiff and the new platform 8 - and the current North Wales Railway Upgrade project, improve the resilience and reliability of the railway, better connecting people, businesses and communities.
“We will continue working closely in partnership with train operating companies so as to deliver safe, reliable, affordable and a growing railway for passengers across Wales and Borders.”
Arriva Trains Wales are now operating more than 1,000 services daily across the Wales and Borders region. This is the highest number of daily services than at any point since the 1960s.
During 2017, Arriva Trains Wales also began publishing more details of its punctuality and reliability, and customers can receive regular updates regarding how different areas are performing by following ATW on twitter at www.twitter.com/ArrivaTW.