Mr Yousaf dismissed recent calls for his resignation to insist the services are getting better and unveiled millions of pounds in new cash to bring forward improvements in the network.
Flanked by First Minister Nicola Sturgeon and Deputy First Minister John Swinney, Mr Yousaf made a crunch statement to MSPs setting out a tranche of improvement measures, including the acceleration of £16 million over two years to upgrade key junctions, track and signalling equipment.
But it came as Dutch operator Abellio was again forced to apologise to commuters after the failure of over-head lines at Finneston in Glasgow caused widespread cancellations across west-central Scotland.
Mr Yousaf told MSPs that the operator had been “much more responsive” in its reaction to the situation than to the disruption caused when a breakdown near Edinburgh Haymarket station last week caused paralysis on much of the network.
“Everyone rightly expects a railway network that operates effectively. So when things go wrong I fully understand the dissatisfaction of passengers and the inconvenience that is caused,” Mr Yousaf said.
“Although there are no guarantees major failures won’t happen, I give my reassurance that ScotRail has learned lessons and is far better prepared for contingencies, including communication with passengers, when such incidents do take place.”
The minister insisted that almost 90 per cent of trains running on time and punctuality improving after weeks of criticism over delays and cancellations prompted rail unions to call for his resignation last week.
Earlier morning commuter services between Inverness and the central belt will begin in mid-December, Mr Yousaf added, with work nearing completion to add additional carriages to peak time services on the Borders rail from December boosting capacity.
The minister has set out plans for a public sector bid to run train services in 2020 if services don’t improve, insisting that the success of ferry operator CalMac shows this can work.
But Tory shadow finance spokesman Murdo Fraser said: “This has been another day of delays, cancellations and disruption, harming our economy and delaying passengers.”
He added that any public sector operator would not be up and running until 2022.
“Mr Yousaf has to understand that passengers don’t want to wait that long, they want improvements now,” he said.
Labour transport spokesman Neil Bibby called on Mr Yousaf to publish his 246 point improvement plan.
Mr Bibby added: “He must also make a commitment to when services will get better – he said it would be March before targets are hit, that surely cannot be the case now.”