Research published by trade unions has found rail fares are on course for a 40 percent increase from 2008 to 2014 - or nearly three times the increase in wage rises.
The news comes on the same day it was announced that some train tickets for services across the border into England could go up by another 4 percent.
What do you think about the rises? How much do you spend on rail travel?
The Trades Union Congress - TUC - says rail passengers will be paying 40 percent more for a ticket in January 2014, than they were in January 2008.
That is nearly three times the rate of wage rises.
Today, we learned that regulated rail fares in England will rise by an average of 4.1 percent from January after the headline rate of retail price index inflation fell to 3.1 percent in July from 3.3 percent in June.
That will affect train users travelling between Wales and England.
The Welsh Government says it is "currently reviewing the options for the setting of regulated rail fares for 2014."
Regulated rail fares in England are set to rise by an average 4.1% from January after the headline rate of retail price index inflation fell to 3.1% in July from 3.3% in June.
Two protests are taking place in Cardiff today as part of a UK-wide day of action against rail fare rises. Unions are warning fares are set to be 40 per cent higher from this January than in 2008.
Commuters in England will find out later how much rail fares are to go up next year. Regulated fares there, which include season tickets, are due to go up by inflation. The Welsh government has yet to decide on fare rises for 2014 but say they will make a decision in due course.
Rail travellers across Wales are facing fresh misery as the cost of the average fare rises by 3.9%. It's 4.2% for season tickets, and some routes are seeing much higher rises. The move comes as motorists have seen an increase in tolls on the Severn Bridges.
Increasing numbers of travellers are reporting a struggle in the costs of getting to work and carrying out essential journeys like food shopping, because of high fuel costs. Hannah Thomas has our report.
Passengers at Merthyr Tydfil railway station this morning were among those confronted by increased fares. There were mixed opinions - some questioned how families were meant to afford rail travel now, but others praised it for quality of service and price, when compared to the alternatives.
Dan Panes, a spokesman for First Great Western, which runs mainline trains from London Paddington to South Wales, says these fare rises are based on the formula set by government, and aims to ensure 'rail fare passengers are paying more for their journeys and taxpayers are paying less.'
Around half of fares are linked to the inflation rate, measured by the retail price index (RPI). These are known as regulated tickets and include most season tickets. Regulated fares have gone up by 4.2% today - overall average fares are up 3.9%.
From today, fares have risen by 3.9% overall. Regulated fares, including season tickets, are up 4.2%.
Campaigners have pointed it it's the tenth successive above-inflation annual rise, and some fares have increased by more than 50% over the last decade.