Disruption caused by train breakdowns and staff shortages has increased since 2011 and peaked in the two years before the Covid pandemic, according to official Office of Rail and Road (ORR) statistics.
The Scottish Tories’ transport spokesperson Graham Simpson pointed to the figures as he underlined the party’s election pledge for automatic refunds for delayed passengers via a planned new smart travel card.
Total delays attributed to “ScotRail on self” by the ORR between 2011-12 and 2019-20 totalled 2.8m minutes – or more than five years’ worth.
That is defined as “issues which the train company could have prevented such as defective trains or a lack of train staff”.
These increased from 289,000 minutes in 2011-12 to 367,000 in 2019-20, after peaking at 369,000 the previous year.
However, they were outweighed by delays caused by Network Rail, which owns all the non-moving parts of the network, including tracks and signals.
The UK Government body was responsible for 4.1m minutes of delays over the nine-year period, which peaked at 659,000 in 2018-19.
The figures cover the last four years of the previous ScotRail franchise, run by First, and the first five years of its successor Abellio’s contract since 2015,
The ORR said no comparable figures were available for the previous nine-year period.
However, it pointed to passenger complaints figures, which it also compiles, which showed a 16 per cent reduction for ScotRail in the second half of 2019-20, when there were 26 complaints made per 100,000 journeys.
Mr Simpson said: “These delay figures will come as little surprise to passengers who have had to endure frustrating delays for far too long on ScotRail services.
“The level of service on ScoRail trains has simply not been good enough.
“Our pledge of a Scottish smart travel card will automatically refund passengers when they go through the misery of delayed or cancelled services.
"It will also allow them to use any form of public transport across Scotland with one simple contactless card.
“The SNP seem to think nationalising services will be a silver bullet for issues like this, but they have failed to outline exactly how that will fix these problems.”
But SNP Transport Secretary Michael Matheson said: "The majority of delays on our railways are caused by infrastructure issues, which is a reserved matter and in the hands of the Tories.
"Making improvements in our rail service also means improvements in rail infrastructure, which remains reserved to Westminster.
"We continue to urge the UK Government to devolve these powers to deliver a better service for the people of Scotland and it is time for the Tories to stop playing political games and back those calls."
ScotRail, which is now effectively run by the Scottish Government, said it was unable to comment because of the election.
However, it pointed out there had been significant punctuality improvements during 2020-21 when performance was above target – even though fewer train ran because of the pandemic and passenger numbers fell by 90 per cent.
A total of 93.1 per cent of trains arrived within five minutes of schedule having called at all their stops, compared to the target of 92.5 per cent.