ScotRail passengers face disruption on seven lines across Scotland until December during work to electrify the main Edinburgh to Glasgow route, it has been announced.
This is in addition to changes already affecting the main line and a secondary route between the cities via Shotts.
Many weekend trains will be replaced with buses or diverted, resulting in lengthened journey times.
The changes from Saturday, October 22, will also involve queuing systems at busy stations.
The ScotRail Alliance, which includes track owner Network Rail, said the improvements would make the Scottish network “rank amongst the very best”.
Among the affected services are Edinburgh to Inverness trains, which will be replaced by buses between Perth and Inverness on November 26 and 27, and December 4 and 11.