Rail passengers in the North East were hit by disruption on the first working day of the year due to a combination of faults and coronavirus-related staff shortages.
Train journeys are being impacted as operators are running reduced timetables in a bid to improve reliability.
It comes after weeks of short-notice cancellations because of staff shortages caused by Covid cases.
ScotRail implemented a temporary weekday timetable on Tuesday as the Omicron variant of Covid-19 has resulted in a "large number of absences".
More than 150 daily services have been cut - including on routes through Newcastle.
National Rail Enquiries also warned passengers that a "problem under investigation" between Darlington and York was causing disruption between the stations.
This affected CrossCountry, London North Eastern Railway and TransPennine Express services.