Rail passengers have been advised to check their travel plans, as the latest phase of improvement works begin.
A revised timetable has started that will last until December.
ScotRail said the engineering work is being carried out to increase “overall reliability” and to pave the way for new electric trains.
Some services will be replaced by buses and queuing systems will be in place at key stations as trains could be diverted, less frequent or cancelled.
An interactive timeline has been created by the rail operator to help customers plan their journeys. Some services will be replaced by buses and queuing systems will be in place at key stations.
The ScotRail Alliance also confirmed that it was working closely with Aberdeen Football Club to help people travelling from the Aberdeen area to attend the Scottish League Cup Semi Final match at Hampden.
It has also been working with the Scottish Rugby Union for fans travelling to the Autumn Internationals at Murrayfield.
Jacqueline Taggart from the ScotRail Alliance said: “We are going through a massive period of change on Scotland’s railway.
“The work that we are carrying out over the next few months will bring about a revolution in rail, with more and better trains, more services and more seats than ever before.
“However, while we transform the railway, there is inevitably going to be some impact on people’s services.
“We are doing everything we can to minimise this, and to keep people moving.”