Rail passengers across the south will today have to fork out for fare rises well above the inflation level.

Customer watchdog body Passenger Focus said rail travellers would ''shudder and shiver'' when they saw the new fares.

But the Association of Train Operating Companies (Atoc) said some fares were staying the same or going down and commuting by rail was ''considerably less expensive than commuting by car''.

From today, regulated fares, which include annual season tickets, will be going up by an average of 6% and unregulated fares, which include off-peak tickets, will be rising even more - by an average of 7%.

There will be 10% rises on unregulated day return fares on London-Weymouth, on South West Trains.

Passengers have been particularly hard hit this year, as the new year price rise is based on whatever the retail price index (RPI) inflation is in the previous July.

The July 2008 RPI was as high as 5%, which meant regulated fares (subject to annual rises of RPI plus 1%) now have to rise by 6%.

Since July the rate of inflation has fallen fast, with the latest RPI being only 3%.

Anthony Smith, chief executive of rail customer watchdog Passenger Focus, said today: ''Many passengers will shudder and shiver when they find out the scale of some new year fare rises. Fare rises that hark back to a time of high inflation and spiralling energy costs look very out of kilter.

''In addition, the perpetual tinkering with ticket restrictions ensure back-door fare rises continue. Yet again, many long-distance passengers will be pushed into paying higher prices or locking themselves into rigid advance-purchase, one-train-only fares.''

Atoc chief executive Michael Roberts said: ''The service offered to passengers is improving all the time thanks to the investment made possible by fares revenues. This year an extra 265,000 trains will be run and £800 million is being spent by operators on trains and station improvements for passengers.

''Not only that, (trains-on-time) punctuality is now at record levels - above 90% - and passenger satisfaction is also high with 80% being very satisfied or satisfied. All of which has taken place at a time when record numbers of passengers are travelling, with an additional one million journeys a week made in 2008.''

London Underground and London bus fares are also rising by around 6%, although some fares will be going up by more than this.

Among the rises are: Arriva Trains 6% (regulated); 6% (unregulated). CrossCountry 6% (regulated); 11% (unregulated). South West Trains 6% (regulated); 7.2%(unregulated). Virgin Trains 6% (regulated); 7% (unregulated).