Financial results for the six months to September show a £747m profit, which the not-for-profit firm set up in 2002 is to spend on network improvements (link below.)
http://news.bbc.co.uk/1/hi/uk/6186552.stmNetwork Rail chairman Ian McAllister said punctuality had improved: "From being a basket case a few years ago , rail is now a success story."
The next objective is getting train punctuality - currently at its highest level for seven years - above 90% , he said.
"We've taken over a billion pounds out of the cost of running the railway , which is good news for the taxpayer and the fact that we're now making money means that we can use that to invest in building the railway."
"Passenger numbers have gone up by approximately 40% over the last 10 years and we think they'll rise by 30% over the next 10 , so we have to plan ahead and that's what we're doing right now."
Increasing capacity was a priority but without building more miles of tracks or double-decker trains , he said.
Instead Network Rail was trying to ease overcrowding by running more trains on existing track , making longer trains and encouraging people to travel outside peak hours.
Network Rail replaced private firm Railtrack in 2002 and receives about £4bn a year in subsidy.
The profits are partly due to delayed payments , because when the rail regulator set the firm's five-year funding levels in 2004 , Network Rail agreed to defer increases in its first two years.
Next week the former chief executive of British Airways , Rod Eddington , will publish his report into the long-term impact of transport decisions on the UK economy.
BBC transport correspondent Tom Symonds said he will resist a French-style "grand projet" such as a high-speed rail link but will advocate using the existing network better and charging drivers for using the roads.
On that note , here is an article entitled "Charging 'could fund new roads'" (link below.)
http://news.bbc.co.uk/1/hi/uk/6186496.stm