Image copyright Getty Images

The reliability of ScotRail trains significantly improved in the weeks after its improvement plan was published, according to new statistics.

The PPM data showed 89.7% of trains arrived within five minutes of schedule in the four weeks to 7 January.

This was a 6% rise on the previous four weeks, and a 2.8% improvement on the same period last year.

But ScotRail's annual performance remains below the 91.3% target set in Abellio's contract for the franchise.

The measure currently stands at 90%, which ScotRail said made it the second best performing large operator in the UK.

The improvement plan, which was drawn up in response to widespread criticism of ScotRail's reliability since Abellio took over the contract in April 2015, was published in full on 29 November.

Child's scooter

It came after Transport Minister Humza Yousaf told MSPs that ScotRail had "learned lessons" following a series of problems with delayed and cancelled services.

Mr Yousaf had previously apologised to passengers and suggested train services could be taken into the public sector in future.

ScotRail said the latest figures were the third period in a row in which its train performance had improved.

And it said the latest improvement came despite overhead line issues at Hyndland on Hogmanay and again on 6 January, and disruption caused when a child's scooter was thrown onto overhead lines at Airdrie.

Collectively, it said these events led to a 0.7% reduction in the monthly PPM score - the key performance measure for the UK's rail operators.

Image copyright PA Image caption Transport Minister Humza Yousaf said the latest figures were encouraging, but that further improvements were expected

The overall PPM for operators in England and Wales for the four weeks to 7 January was 87.1% - almost three percentage points lower than the ScotRail figure.

ScotRail handled 6.7 million passenger journeys on about 57,000 train services over the period.

'Biggest upgrade'

A traditionally busy time of year, three of the busiest five days of 2016 were recorded in December - on the 12th, 16th and 17th of the month - as passengers started to enjoy the festive season.

ScotRail Alliance managing director Phil Verster said the latest figures showed that its Performance Improvement Plan was starting to produce results, which were being achieved in the middle of the "biggest upgrade to our railway since Victorian times".

But he said the operator was committed to "doing more and going higher".

Image caption A child's scooter caused disruption to the rail network after it was thrown onto overhead lines near Airdrie

Mr Verster added: "The sheer scale of the work we are doing to improve the railway has resulted in more disruption than normal. This means that our customers have had to put up with a lot over the past few months.

"We have done everything we can to keep people moving during this unprecedented period. I hope our customers can take some encouragement from the continued improvement."

Modernisation work being done by ScotRail includes the introduction of new faster, longer, greener trains, which it has said will dramatically increase the number of seats available and help to reduce journey times.

Responding to the latest figures, Mr Yousaf said the improvement was "encouraging" and remained "much higher" than the England and Wales average.

'Overcrowded trains'

He added: "I expect to see further improvements over the coming months, although I accept some disruption during the winter weather will be inevitable.

"When problems do happen, measures must be taken swiftly to rectify the situation and, crucially, passengers must be kept informed."

Opposition parties insisted that too many commuters were still suffering from delays and cancellations.

Scottish Conservative MSP Liam Kerr said: "It's all fine and well publishing these figures, but commuters know that they are still not receiving a good enough service.

"Every day they are forced to put up with delayed and overcrowded trains, and many have simply had enough."

And Scottish Labour transport spokesman Neil Bibby said: "Humza Yousaf said he expected ScotRail to hit their performance targets by the end of March, yet here we have another set of figures showing contractual targets are still being missed.

"The clock is ticking for Humza Yousaf and ScotRail."