The tunnel outside Glasgow’s Queen Street station is set to close for five months for essential works.
Ugrades to the tunnel will allow swifter, longer electric trains to operate on the main line between Edinburgh and Glasgow.
Route diversions will mean most journeys will take up to 25 minutes longer with queuing systems in place to enter and exit Queen Street Lower level station.
Rob Shorthouse, Communications Director at the ScotRail Alliance said: “We are just days away from the start of the biggest, most important improvement to Scotland’s rail network for many years. The upgrade work at Queen Street Tunnel allows us to run faster, longer greener electric trains in the future. This will mean more seats, shorter journey times and reduce our impact on the environment.
“We have spent the last few weeks doing everything we can to make sure customers understand the changes to journeys that are necessary. However, with just a few days left, we are urging anyone who has not yet planned how they will travel for the next five months to do so. Trains are running, we are open for business. However, some services are being diverted and journey times will take longer than normal.”
This week also marks the first services of three new Class 320 electric trains. The first of seven new trains sets, they will add 21 an extra carriages and more than 14,000 extra seats to the current ScotRail fleet.