The Government today announced £4.2 billion worth of new rail schemes, including electrification of the Midland Main Line.
Added to £5.2 billion of already-announced projects, the new money takes the amount to be invested in the railways between 2014 and 2019 to £9.4 billion.
Prime Minister David Cameron hailed the plans as "the biggest modernisation of our railways since the Victoria era".
But the Office of Rail Regulation (ORR) warned that it was now necessary to ensure the plan was affordable and deliverable.
Campaigners said they feared the promised investment would mean further high increases to season tickets that are, in any case, due to go up by 3% above the RPI inflation level in January 2013 and in January 2014.
Projects that have already been committed to the 2014-19 period included the completion of the ongoing Crossrail and Thameslink schemes, and electrification between London and Cardiff, Manchester to Liverpool and Preston and across the Pennines.
The £4.2 billion worth of new schemes include:
:: Upgrades to stations and tracks creating enough capacity around cities for an additional 140,000 daily rail commutes at peak times. This includes £350 million for lengthening of platforms at London's Waterloo station;
:: Faster journeys and more train capacity from £240 million of improvements along the East Coast Main Line from north-east England down through Yorkshire, Lincolnshire and Cambridgeshire to London;
:: The creation of a high-capacity "electric spine" running from Yorkshire and the West Midlands to South Coast ports. This comprises an £800 million electrification and upgrade from Sheffield - through Nottingham, Derby and Leicester - to Bedford, completing the full electrification of the Midland Main Line out of London St Pancras and electrification of the lines from Nuneaton and Bedford to Oxford, Reading, Basingstoke and Southampton;
:: Taking electric rail beyond Cardiff to Swansea, completing the full electrification of the Great Western Main Line out of London Paddington at a total cost of more than £600 million, and electrifying the Welsh Valley lines, including Ebbw Vale, Maesteg and the Vale of Glamorgan;
:: Completion in full of the "Northern Hub" cluster of rail enhancements with the approval of £322 million of outstanding track and capacity upgrades across Manchester city centre, Manchester Airport and across to Liverpool.
These are in addition to £477 million of Northern Hub schemes already approved across the north of England such as electrification of the North Trans-Pennine route between York and Manchester.
:: A new £500 million rail link between the Great Western Main Line and Heathrow.
Mr Cameron said: "From Crossrail, high-speed rail and now the billions of pounds of investment we are announcing today, this Government is committed to taking the long-term decisions to deliver growth and jobs.
"In what is the biggest modernisation of our railways since the Victorian era, this investment will mean faster journeys, more seats, better access to stations, greater freight links and a truly world-class rail network."
Deputy Prime Minister Nick Clegg said the investment would "help people to choose trains over cars, reduce carbon emissions and provide a rail system that is faster, more reliable and greener".
Chancellor George Osborne said he was particularly pleased about the the Northern Hub plans, while Transport Secretary Justine Greening said the Government was "focused on delivering an affordable, reliable and faster railway network that drives jobs and growth".
ORR chief executive Richard Price said the Government's plan set out "a massive programme of investment".
He went on: "We now need to ensure that the plan is affordable, and to work with the rail industry to set out in detail how it can be delivered."
Shadow transport secretary Maria Eagle said Labour had announced electrification plans in 2009 and it was "a bit rich" for coalition Government ministers now to take credit, "not least when they have spent the last two years delaying these schemes".
Anthony Smith, chief executive of rail customer watchdog Passenger Focus, said: "Passengers will want to see the Government avoid above-inflation fare increases. These investments must be delivered in a cost-effective way."
Campaign for Better Transport chief executive Stephen Joseph welcomed the investment news, but added: "Pricing people off the railways will mean many passengers simply won't be able to afford the benefits this investment will bring."
Transport union TSSA called for the RPI plus 3% fare rises to be scrapped, while the RMT transport union said what was needed was "investment today, not a political promise of jam tomorrow".
Network Rail said there would be tough targets to meet "made even more challenging with the need to deliver record numbers of services on essentially Victorian infrastructure".