The woman, who asked not to be named to protect her 81-year-old's privacy, said she her mother was travelling back to Wagga after a family visit late last month when her journey blew out to 13 hours.

The family's horror experience coincidences with the release of new punctuality data that show the majority of the XPT trains through Wagga do not reach their final destination on time.

In the six months to January, XPT punctuality on the South Line through Wagga ranged from between 31.5 and 45.5 per cent.

"My mum is 81 years old and she doesn't have a mobile phone. She has rheumatoid arthritis so it's too difficult for her to use one," the woman said.

"We put her on the train at 7.40am on January 28. She had organised for one of her friends to collect her at Wagga station.

"It wasn't until 1.51pm that I received a text from TrainLink that there was a mechanical issue and major delays."

The woman said she tried to get more information about the delay as she was worried about her mother's ability to cope with the heat.

"A 4.26pm I got another text saying the service would terminate at Yass and there would be a road replacement coach.

"I called state rail to advise that my mum was elderly, unwell, travelling without a phone and does not cope with heat well and may need some assistance and I would like someone to see if she was OK.

"I was told by state rail that all their customers were important. They just didn't seem to understand that my mum would need some extra assistance."

The service eventually arrived at Wagga after the passengers were left to sit in the train while the carriages sat idle on the tracks for three hours.

In response, a TrainLink spokesperson said the service was "committed to seeing our customers reach their destination on time and work hard to ensure these services are delivered in a safe and timely manner".

"There are a range of factors that can impact the reliability of services along the 5892 kilometres of track we use including track and signalling issues, emergency situations, extreme weather conditions and stationary freight trains," the spokesperson said.

"There are also limited paths for passenger trains on some of our lines, due to a high volume of freight services operating."

TrainLink rail services are measured for reliability at their final destination and determines determined to be "on time" when arriving within 10 minutes of the timetabled arrival time.

The performance target was 78 per cent of services being on time, but the XPT line through Wagga has not met that target since August 2018, when it recorded 82 per cent punctuality.

"There are a range of factors that can impact punctuality of services, some of which are beyond our control," the TrainLink spokesperson said.

"The main line between Sydney and Melbourne, is one of the busiest mixed freight corridors in Australia and this can impact punctuality of services.

"All partners continue to work together to improve the line and ensure our services run to schedule."