Rail fares will rise by 6.2% in January
Some rail fares in England will rise by 6.2% in January - about double the rate of inflation - although other price rises may be higher.
The Retail Prices Index (RPI) measure of inflation in July - which stood at 3.2% - is used to calculate the rises.
Some English fares will rise by RPI plus 3%, while in Scotland they will go up by RPI plus 1%. Wales has yet to set a figure for its increase.
The extra money is helping to fund huge investment across the network.
There are no fare increases currently planned in Northern Ireland, where fares are not linked to RPI, after a 3% rise in April.
Chance of higher rises
The decision to have different formulas for fare rises is a political one. In Scotland, 75% of the cost of the railways comes from a government subsidy - higher than in England.
The figures for planned rises in England and Scotland are an average across regulated tickets, which make up half of all fares. These regulated fares include season tickets and off-peak intercity journeys. In Scotland, this does not include the busy shuttle service between Edinburgh and Glasgow.
Some passengers could see their journey prices rising by more than the average, as train companies are allowed to increase them by up to five percentage points more, as long as they cut ticket prices elsewhere.
Passengers will not be told yet how prices will change on their specific route. The latest figure sets the template for this rise.
Those who travel across a border, such as from Scotland to England, will be subject to the higher English fare rises.
Mike Hewitson, of watchdog Passenger Focus, said: "This is another inflation-busting increase.
"There is only so much you can squeeze passengers. The government needs to think again about the plus 3% [formula]."
BBC transport correspondent Richard Westcott says passengers and taxpayers used to split the cost of running the railways, with both sides paying about half each, but successive ministers have cut the amount of government funding and that has resulted in regular fare rises.
The latest rise means fares in England will have gone up by more than inflation for 10 successive years, resulting in some of the most expensive train journeys in Europe although some tickets booked well in advance can be cheap, our correspondent adds.
'You have to stand'
Passengers have reacted with disappointment.
One disgruntled passenger told the BBC: "I don't think it's good value for money at all. Every train I get in the morning, you either have to stand up or you can't get in."
Stephen Joseph, from passengers' group the Campaign for Better Transport, said rail fares could rise three times faster than salaries if the government sticks to its policy.
"With the economy flatlining, this is untenable. The government knows they can't continue to hit commuters - that's why they've postponed the fuel duty increase," he said, as activists from the group protested against the anticipated increases at London's Waterloo station.
"Now they need to give the same help to rail users."
The group said commuters across the country routinely spend between 5% and 10% of their salary getting to work. In some towns in south-east England, it said they spent up to 15%.
TUC general secretary Brendan Barber said: "Commuters could see the price of their season ticket going up three times faster than their pay rise.
"In return for these whopping fare increases, rail travellers can expect cutbacks to services and more unmanned stations, creating safety risks for those travelling at unsociable hours."
But Michael Roberts, chief executive of the Association of Train Operating Companies, said: "It has been government policy during the past eight years for passengers to pay a larger share of the cost of operating the railways and to focus taxpayers' money on investing in longer-term improvements to the network.
"Any flexibility train companies have within the rules is to maximise revenue for the government."
Transport Secretary Theresa Villiers said that the fare increases were necessary in the short-term to achieve the government's long-term goal of bringing down the cost of running railways.
"In the longer term we are determined to get rid of these above-inflation fare rises all together," she said.
"But in the meantime I'm afraid these fare rises are going to be necessary in order to help us deliver a rail investment programme at a time when the deficit means public spending needs to be constrained," she added.
Shadow Treasury minister Rachel Reeves said: "These fare rises are unacceptable at a time when families are already struggling to make ends meet and wages are stagnant at best."
The official inflation figures from the Official for National Statistics show that the Consumer Prices Index measure of inflation rose from 2.4% in June to 2.6% in July. The rise in the rate of CPI follows three months of falls. RPI rose to 3.2% from 2.8% in June.