Tayside rail commuters are facing almost half a year of delay misery on the Glasgow line.
The ScotRail Alliance confirmed 25 minutes will be added to journey times for customers travelling to the west coast city from Dundee, Arbroath and Carnoustie.
All services from the three stations will be diverted to either Glasgow Central or Glasgow Queen Street Low Level when the High Level tunnel at Queen Street closes for 20 weeks.
Starting on March 20, the diverted route will cause a headache for passengers at peak commuter times.
The normal timetable is expected to resume on Monday August 8.
A major publicity campaign to ensure customers have all the information they need to keep moving is due to commence within weeks.
The £60m project will renew nearly 2km of ageing track through Queen Street tunnel and enable faster, longer, greener trains to operate on Scotland’s rail network from later this year.
A ScotRail Alliance spokeswoman said: “By diverting trains into Glasgow Queen Street Low Level or Glasgow Central, we’re ensuring our customers who use services from the north east area will still have a direct link to the city.
“Upgrading the tunnel will allow us to run faster, longer, greener trains in the future.
“This will mean more seats, shorter journey times and less impact on our environment.
“The long term benefits of this investment will be considerable, not just for our railway, but also for the country.”
A dedicated webpage
scotrail.co.uk/QueenStreetTunnel
has more information.