Growth was higher in the summer months with an 8% year-on-year rise. Demand was also up in the final quarter despite two instances of heavy snowfall in December that severely impacted services.
A 15% rise in the cost of petrol in 2010, more frequent services on some routes and high punctuality are being cited as some of the reasons that more and more people are using the train along with an improvement in the economy.
Atoc also says that growth was partly driven by people taking advantage of cheap tickets. For example, the sale of Advance tickets rose 12% compared with 2009, and the average price of a single journey fell from £5 to £4.96.
"Passenger rail supports thousands of businesses and helps millions of people every day to get to work, meet friends and family, or just to get out to have fun," says Mr Michael Roberts, chief executive of Atoc. "The challenge will be to continue this growth in 2011."