Rail passengers will see the average price of their tickets increase by 3.5% from January, according to figures out today.
The current formula also allows rail companies to increase some fares by an extra 2%, meaning that some tickets could increase by 5.5%.
Fares can be increased in January by 1% plus July's Retail Prices Index inflation figure.
Rail travel is being pushed "out the reach of some ordinary people" by fare increases, the head of a public transport advocacy group said.
Stephen Joseph, executive director of the Campaign for Better Transport, told Good Morning Britain that Government-dictated ticket price hikes mean rail fares are rising four times faster than wages.
Commuters will find out how much rail fares are likely to rise by next year when the Retail Price Index (RPI) for last month is released today.
The annual increase is capped at July's RPI plus 1%, with an extra 2% added to some tickets.
Rail fares have been rising faster than the rate of inflation for more than a decade. So how do you make your money go the furthest by rail?
What could the impact of rail fare rises be on your wallet? Compare selected season tickets before and after the forecasted rise.