Hopes are rising that a deal could be struck this week to end the disruption on Scotland's railways.
The union representing the train drivers involved in a pay dispute with ScotRail is hopeful that a resolution is possible in the coming days.
Aslef and ScotRail's latest talks were adjourned yesterday after a 90-minute meeting.
The union rejected the train operator's latest 4.2% pay offer last week, but is due to return to discussions this week.
The row has had a major impact on services, after drivers refused to work on their rest days.
It led to ScotRail introducing a temporary, greatly-reduced timetable to provide "greater certainty".
Economist Tony Mackay has estimated this could cost the Scottish economy between £75million and £80million every week from a combination of the fall in economic output and extra money having to be spent by travellers to get to their destinations.
The train operator was nationalised by the Scottish government in April.
ScotRail described the latest talks as "constructive".
Kevin Lindsay, Aslef's Scotland organiser, told the BBC that both sides had a "bit of work to do".
"Both sides have explored what was on the table previously.
"Both sides have tabled ideas and both sides are now away to look at them and will resume talks later in the week."
He added: "If ScotRail continue to talk in the manner they are talking I can see us reaching somewhere, but if they don't I can see us reaching industrial action."
Aslef previously rejected a 2.2% pay deal, before later being offered 4.2% and improved conditions - which Transport Minister Jenny Gilruth said she was "hopeful" would be accepted.
David Simpson, ScotRail's service delivery director, said yesterday: "The meeting with Aslef was constructive and further talks will be scheduled for later this week.
"It's positive that Aslef has recognised that the negotiations need compromise and have been willing to explore further the significantly-improved offer that has been made.
"We're hopeful we can resolve the current dispute and work together to encourage people back to the railway."
Transport Scotland - the government's transport agency - described the latest offer as being "both fair and affordable".