RAIL operator Northern is cracking down on fare dodgers on the Airedale line.

Anyone not buying a ticket before boarding a train will face a £20 fine, or 'penalty fare'.

Or passengers could have to fork-out double the cost of a single ticket to their destination.

"Sadly there is still a minority who believe they have a right to travel without buying a ticket," said Paul Barnfield, Northern's regional director.

"Their actions reduce the overall income of the rail industry and the money available to invest in further improvements.

"Everyone who travels by train should have a valid ticket or pass, or must be able to demonstrate they have made every effort to buy a ticket before they boarded."

He says the new system, which comes into effect on December 6, is a "natural extension" of a buy-before-you-board campaign launched last year.

And he said the wide range of options now available for passengers to buy tickets meant there were no excuses to travel without one.

"We have invested in new state-of-the-art ticket machines at all stations on the Airedale and Wharfedale lines," he added.

"These machines offer a full range of fares, including discounts.

"With online and mobile ticketing, as well as ticket offices at our staffed stations, there is really no reason for anyone to board a train without a valid ticket.

"For customers who want to pay by cash, our ticket machines will issue 'promise to pay' notices which can be exchanged – along with a cash payment – for a ticket when on board the service or at the next available ticket office."

Penalty fares are already used by many other train operators.

The system, which has been in operation for more than 20 years, works to a national set of rules which includes signs and warning notices at stations.

There is also an appeals process.

Posters explaining the system will be displayed at all stations on the Airedale line and leaflets will be handed out.

More details can be found at northernrailway.co.uk/penalty-fares.