Network Rail has a target of 93% punctuality on its busiest routes
Network Rail is promising improvements will mean fewer delays and less overcrowding on trains - despite having to cut its budget by 20%.
A five-year programme of maintenance and improvements worth nearly £12bn is due to begin on Wednesday.
The company is promising to cut delays caused by infrastructure - for which it is responsible - by 25% before 2014.
Many of the projects are designed to reduce overcrowding by lengthening platforms and improving signalling.
The improvements are part of an overall £35bn spending programme for 2009-14, which includes replacing older parts of the network, day-to-day maintenance and safety costs.
In October, the Office of Rail Regulation gave Network Rail (NR) a target of increasing the figure for trains running on time to 93% on the busiest routes in south-east England - a 3% improvement on current figures. Elsewhere, the target was set at 92%.
The regulator also gave the green light to a number of major railway projects - including improvements on the Thameslink route that crosses London from north to south, the rebuilding of Birmingham New Street station and a new line to Glasgow airport.
But Network Rail confirmed that it was £210 million short of the amount needed to provide some of the extended platforms needed to accommodate longer trains that will be coming into service.
Not all the traub doors will open at some stations where platforms will not be extended.
NR is confident it can deliver the improvements despite the decrease in its budget.
A spokesman said: "Network Rail recognises that it has tough challenges ahead to bring about the massive improvements for Britain's railways, and delivering efficiencies and providing better value for money will be one way we will do this.
"Billions have already been cut from the cost of running the railway. The next five years will be focused on doing the basics even better and delivering a bigger, better railway for passengers and freight.
"We will also provide even better value for money for the British people - making savings of an extra 21% - on top of the 27% already achieved since 2004."
Five-year funding plans for the rail network were introduced following privatisation.
NR chief executive Iain Coucher promised "transformed stations, increased speeds and unblocked bottlenecks".
He said: "The next five years will see massive investment in improving the railways for passengers and freight users by adding capacity and relieving overcrowding.
KEY RAIL PROJECTS 2009-14
Birmingham New Street
Glasgow airport link
Spending by Network Rail
"We will see a transformed railway through ambitious plans that will deliver more trains, more seats, longer trains and faster trains.
"Services will be even more reliable, delays caused by the infrastructure will be cut by nearly 25% and we will embark upon an investment programme that is bigger and more ambitious than anything seen in a generation."
Michael Roberts, chief executive of the Association of Train Operating Companies, said the investment programme was a "major opportunity to provide a better railway for passengers".
"Delivery is now the key and its success will depend on all parties working together," he said.
"Network Rail will need to redouble its recent moves to improve the speed and efficiency with which it undertakes projects large and small."
Transport Minister Lord Adonis said: "The scale of today's plans and the level of our investment demonstrate our will to deliver a rail network that Britain can be proud of."
Shadow transport secretary Theresa Villiers said it was vital NR kept spending under control.
She added: "For too long, passengers have been subjected to a depressing combination of chronic overcrowding and soaring fares, and NR needs to play its full part in tackling those problems."
Liberal Democrat transport spokesman Norman Baker accused NR of a lack of ambition.
He said: "Passengers have been let down by the rail network for years and this investment will not do nearly enough to turn this sorry state around."
Bob Crow, general secretary of the RMT transport union, said: "No amount of spin can disguise the hard reality that NR is under a huge financial squeeze and has shelved nearly a third of the track renewals projects it had already scheduled for this year."
Anthony Smith, chief executive of watchdog group Passenger Focus, expressed satisfaction that the plan addressed what he said were rail users' main concerns of punctuality and overcrowding.
He said: "Passengers will welcome the commitment the industry and government is making to improve the railway and the certainty of detailed plans for the next five years."
Baroness Valentine, chief executive of business group London First, said that with two-thirds of rail journeys starting or ending in the capital, NR had to tackle "chronic capacity shortages" on commuter routes.
"NR has promised more trains, more seats and better journeys in its delivery plan for the next five years. London's growth and future success depend on all three," she said.
The rail infrastructure company was heavily criticised for problems during its upgrade work on the West Coast main line, and is under pressure to improve the network without causing serious disruption to passengers.