Image copyright PA Image caption Commuters delayed at Waterloo station

The man tasked with working out how to improve UK railways says a "Fat Controller" type figure, independent from government, should be in charge of day-to-day operations.

The former boss of British Airways, Keith Williams, said government involvement should be limited to overall policy and budget decisions.

But he said the Department for Transport should not manage the system.

His review of the rail system will be published this autumn.

The Fat Controller is a fictional character who manages the railways in Thomas the Tank Engine, the children's television series based on The Railway Series books.

Mr Williams said he also believed that, in the future, rail franchises should be underpinned by punctuality and other performance-related targets.

The government launched the review after passengers in northern and southern England experienced chaos over several weeks last summer following the introduction of a new timetable.

By December, punctuality across the country had dropped to a 13-year low.

Media playback is unsupported on your device Media caption 'Somebody needs to be accountable to the public'

In a BBC interview Mr Williams insisted the interests of passengers would shape every aspect of his work and that the creation of an individual or organisation with oversight of the entire rail system would be "key for regaining public trust."

"Someone needs to be accountable to the public," he said.

He is still to decide on what relationship the individual or organisation would have with government but he said Network Rail, the public company managing rail infrastructure, should not take on an overall managerial role.

The idea has echoes of the Strategic Rail Authority, a body which, from 2001 to 2006, provided "strategic direction" for the industry.

Mr Williams had already said that the current rail franchising model was finished, but he has now indicated that a franchise should last longer than the current average of seven to eight years.

Performance targets

He argues that if train companies were in charge of networks for more time they would have more incentive to invest.

As things stand, under a franchise agreement, a train company will make a series of commitments to the government which have to be delivered.

According to Mr Williams, a franchise should no longer be about "how many ticketing offices there are in a station".

Media playback is unsupported on your device Media caption Hydrogen trains: Are these the eco-friendly trains of the future?

His team is looking into how franchises could focus instead on performance targets such as punctuality and whether or not services have the correct number of carriages - something which continues to be a problem for passengers in the north of England.

The rail review also looks set to recommend an overhaul of the complicated rail ticketing system, which has not been reformed since the mid-90s.

"Pay-as-you-go across regions and cities has been difficult to implement because of the fares system that exists today," said Mr Williams.

He said a national system should be created to allow more third-party companies like thetrainline.com to improve the way people buy tickets.

Mick Cash, general secretary of rail union RMT, said it had warned that "Keith Williams had been hand-picked by Chris Grayling and the Tories to try and get them off the hook over the privatised chaos on our railways".

He added: "RMT also warned that Keith Williams would side 100% with his big-business mates and duck the issue of public ownership of the railways - the option supported by over two-thirds of the British people.

"He has and after months of deliberation has come up with the classic cop-out of another unaccountable quango."