Rail passengers travelling without a ticket will be fined from Monday on lines where they could previously buy tickets on board.

As part of Transport for Wales’ (TfW) penalty fare zone expansion, travellers on South Wales lines and the Welsh Marches line could be fined either £20 or double their ticket fare, whichever is greater, if found to be dodging their fare.

TfW said the expanded zone was to tackle fare evasion which costs them “millions each year” in revenue.

But some rail passengers on the affected Rhymney line were not pleased by the changes, and John Davies, 80, said the ticket machines were “not very friendly at all” so he relies on buying his ticket on the train.

Mr Davies, from Newbridge, Caerphilly, said the fines were “another slant at the old age pensioner and the working people who use the trains”.

The penalty fare zone already includes journeys between the Severn Tunnel Junction and Carmarthen, where the fine is £20, and the Shrewsbury to Birmingham line, which is considerably steeper at £100, in line with English operators.

The addition of South Wales Metro routes will include Treherbert, Aderdare and Merthyr lines plus Rhymney, Ebbw Vale, Barry and the Vale of Glamorgan line.

Passengers are being advised to buy a ticket prior to travelling, either online, at the station or use the pay as you go system.

But the adjustments have sparked concerns among passengers over the age of 60 about operating the ticket machines for concessionary tickets.

Cheryl Russell, 65, said the ticket machines at the stations do not allow her to apply a senior discount.

“I have always bought them on the train. I’m not happy and I won’t be going to Cardiff on the train, I would rather use my bus pass instead,” she said.

“Anyone who holds a bus pass, it will impact all of us.”

Sarah Cogbill, 37, thinks the fines could put people off from using trains altogether.

“They want people off the roads, but they need to make transport easy,” she said.

“If people are going to be fined, they are going to jump in the car.”

Ms Cogbill, from Pengam, said the added minutes spent buying a ticket make all the difference when you are travelling.

She added: “They need to try it themselves and think about people’s day to day.

“When you have busy lives, working, children, getting stuck in traffic, it is a nice convenience to be able to buy the ticket on the train without the risk of being fined.

“It is going to inconvenience people, and mainly workers.”

TfW manages 248 stations, including all 223 in Wales, plus a number over the border.

The £100 penalty fares only apply for TfW services between Shrewsbury and Birmingham.

If you start your journey at stations where ticket buying facilities are not available, you will not be liable to a penalty fare.

Alexia Course, chief commercial officer at TfW said the process was not to unfairly penalise people but to “identify deliberate acts of fraud”.