Aberdeen rail passengers are facing months of bus replacement services.
People travelling between the Glasgow and Aberdeen will face nine months of disruption on night services on Monday to Thursday and Sundays.
ScotRail has warned passengers that some journey times will be longer and that queuing systems will be in place at stations were replacement bus services are in operation.
Passengers heading to Glasgow from the Granite City on services arriving in Stirling after 9pm on the affected days will be required to transfer to a bus for the rest of the journey.
Those people heading north to Aberdeen will be required to take the replacement bus service from Glasgow to Stirling. A train will take passengers the rest of the way.
The bus replacement services will be in operation on Monday to Thursday between September 11 and May 17, 2018.
The Sunday changes will come into effect on December 7.
From December 10, rail services to Aberdeen on a Sunday after 9pm will start at Perth, with buses taking passengers from Glasgow. This will be in effect until May 20, 2018.
Dons fans planning on travelling home from Glasgow after the Rangers game on January 24 will be forced to use the replacement bus service, which could see their journey time home increased.
ScotRail Alliance infrastructure director David Dickson said: “The work we will be doing will help deliver the best railway Scotland’s ever had, with faster journeys, more seats and better services.
“The railway will be open for business while we carry out this essential work.
“People travelling during morning and evening peak times will not be affected, and will be able to travel hassle free.
“Where we have had to change services, we will keep people moving by providing replacement bus services.
“We would encourage customers to visit scotrail.co.uk/improvements to find out more information about the changes.”