Media playback is unsupported on your device Media caption Dave Higgins, chief executive of Network Rail: ''We haven't invested to meet demand (in the last 50 years) and playing catch up is always more expensive''

A £37.5bn plan to develop the UK's railway infrastructure over five years has been announced by Network Rail.

The plan, covering the five years up to 2019, promises faster journeys, 170,000 more peak-time commuter seats and improved reliability, but depends on making savings and rising fares.

Consumer group Passenger Focus welcomed investment but said it was important to keep travel costs "under control".

Network Rail said it needed to invest now to create a more resilient railway.

Its plans include:

Spending £600m protecting tracks and bridges against floods and heatwaves and adding 1,000 miles of new electrified lines including the Great Western and Midland Main Lines

Seeing 225 million more passengers per year and 355,000 more trains in service - the highest numbers ever

Providing 20% extra morning peak seats into central London and 32% into large regional cities in England and Wales

Providing 700 more trains a day linking key northern England cities and a 10-minute reduction in journey times between Manchester and Leeds

Spending £1bn to improve the network in the South and South West

A move away from more than 800 signal boxes to 14 major operations centres

Station improvements at Birmingham New Street and Reading, Berkshire, and some £4bn improvements for Scotland including reopening 31 miles of railways closed nearly 50 years ago

Network Rail says it aims to reduce the cost of running Britain's railways by a further 18% and cut annual public subsidy to between £2.6bn and £2.9bn in 2019, down from £4.5bn in 2009 and £7bn in 2004.

Resilient railway

However, the plans will be affordable only if Network Rail manages to make these savings. It also assumes fares will keep rising by more than inflation every year to help pay for it.

Analysis This is an ambitious wish-list that could make a real difference to train passengers, but money is going to be an issue. For starters, Network Rail needs to save £3.1bn between 2014 and 2019. Swapping 800 old signal boxes for 14 swish new operating centres is one plan which they say will save £250m a year, without, they insist, compulsory redundancies. Then there is safety. The old way of checking a track was to have 30-odd people walking along it, now they have computerised trains carrying two or three people. Still, saving that kind of cash is a major challenge and they will be under intense pressure not to compromise on safety or jobs to achieve it. Raising the money depends on inflation staying low, passenger demand staying high, the commercial property market remaining steady and the next government sticking to the current fares policy of yearly, above-inflation rises. In the current climate none of that is certain, which means some of these fancy new plans might get mothballed if something goes wrong.

BBC transport correspondent Richard Westcott said that could mean at least six more years of big price rises, on top of the 10 years passengers have already experienced.

Network Rail chief executive David Higgins told BBC Radio 4's Today programme: "We have an amazing railway which is performing out of its socks, but it is still an old, Victorian railway which costs money to maintain because it is old and at a very, very high level of capacity, so getting access to the railway is really difficult.

"But we have made huge progress. The costs of maintaining and operating the railway in the 10-year period to 2014 have come down by 50%. We have to invest to save. We have to spend now to increase capacity, create a more resilient railway."

Anthony Smith, of consumer group Passenger Focus, said passengers would be pleased to see Network Rail and the train companies "planning together to keep investing to meet key passenger priorities as shown by Passenger Focus research".

Media playback is unsupported on your device Media caption Music mogul and rail enthusiast Pete Waterman gives his reaction

He said providing extra seats to tackle overcrowding and continuing to get more trains on time was "welcome".

However, he added: "Getting costs under control is also a key industry priority to help keep the lid on future rises."

Michael Roberts, chief executive of the Association of Train Operating Companies, said: "Early clarity from government on the franchising and regulatory framework for rail will be vital in allowing train companies, Network Rail and our suppliers to deliver the best possible deal for passengers and taxpayers."

Manuel Cortes, leader of the TSSA rail union said rail passengers had already suffered enough above-inflation fare rises.

"They should not now be expected to face another six years of even higher fares. No-one expects motorists to pay more for new roads or air passengers to pay for new runways." he said.

Network Rail's business plan was unveiled just days after rail fares for season ticket holders in England, Wales and Scotland rose by an average of 4.2% as the annual price hike, announced in August, came into effect.

Overall, ticket prices increased by 3.9%, although rises varied between train operators.

It prompted the TUC to claim that average train fares had risen nearly three times faster than average incomes since 2008.