Train travellers will face mid-winter misery in January when train fares rise by an average of 6.2%.

The increase was announced today by the Association of Train Operating Companies (Atoc).

The organisation gave no details of what the rise would be for each individual train company.

But the 6.2% figure is only an average rise, so that some fares could be going up even more.

Gerry Doherty, leader of the TSSA rail union, said the rise was ''simply outrageous''.

Atoc also failed to break down the figures into regulated fares - which include season tickets and account for around 40% of all fares - and unregulated fares.

Under the current annual price cap formula, fares can only increase each January by the previous July's RPI inflation rate plus 1%.

This means that in January 2011, regulated fares will rise by an average of 5.8%. Passengers on services run by the Southeastern train company have their own personal price formula of RPI plus 3% due to the extra investment in services which include the 140mph Javelin trains.

The 5.8% figure thus becomes 7.8% for the Southeastern customers whether they use the new Javelin trains or not.

As the January rise is only an average figure, some regulated fares could go up by as much as 10%.

And further misery will await passengers in January 2012 when the annual price rise formula changes to RPI plus 3% across the network.

Atoc chief executive Michael Roberts said today: ''We know times are tough for many people but next year's fare increases will ensure that Britain can continue investing in its railways.

Daily Echo: Click below to see a video of today's headlines in sixty seconds

''Even with these fare increases, the money passengers spend on fares covers only half the cost of running the railways - taxpayers make up the difference. The Government is sticking with the previous administration's policy to cut the taxpayers' contribution to the overall cost of running the railways.''

He went on: ''More and more people are travelling by train and demand is expected to double in the coming decades so it is more important than ever that money is spent on providing better stations, more trains and faster services. Money invested through fares has helped to bring about the record levels of customer satisfaction and punctuality on the railways today.

''But, in the longer term we need reform which drives down the cost of the railways by relying more heavily on the innovation and resources of the private sector to give passengers a better service and taxpayers better value for money.''

Mr Doherty said: ''It is simply outrageous that hard pressed commuters are being forced to pay fare hikes of up to 10% when they are themselves facing pay freezes and job cuts.

''We will see fares soar by 30% over the next four years as ministers and private train companies hold passengers to ransom with the lifting of the fares cap formula.

''Ministers claim this is to pay for a better railway. Passengers will regard that as a sick joke seeing as we have the most expensive and overcrowded railway in Europe.'