Rail services between Glasgow and Edinburgh are to return to normal a day earlier than planned after a 20-week repair project.
Commuters have faced longer journeys for five months due to the £60 million upgrade at Glasgow’s Queen Street Station.
The station’s high-level tunnel, used by Edinburgh, Aberdeen and Stirling services, has been closed since March, with services originally due to restart on Monday, August 8.
ScotRail has now said the tunnel will open a day earlier, with normal services resuming on August 7.
Diversions caused by the work has meant most journeys take about 25 minutes longer than usual.
Phil Verster, managing director of the ScotRail Alliance, said the project has been “one of the most significant pieces of work ever carried out on our railway”.
“I’m delighted to confirm that we will be able to reopen the Queen Street tunnel a day ahead of schedule,” he said.
“This has been an extraordinarily complex job. Our people have been working round the clock, often in really challenging circumstances, to get this job done. This has been one of the most significant pieces of work ever carried out on our railway.
“That we have managed to do it while still keeping people moving is testament to the hard work and dedication of our staff.
“I’m incredibly grateful to our customers for the patience and understanding that they have shown over the course of the last five months.”
Work to redevelop the concourse of Queen Street station is expected to start later this year and continue until 2019.
Transport minister Humza Yousaf said: “I am pleased that the work in Queen Street tunnel has completed on schedule and, like all rail passengers, I am looking forward to the resumption of normal services. I would like to thank the public for their patience during the closure.”
Commuters have also been hit during the tunnel works by a series of one-day strikes led by the RMT union.
The dispute centres round the RMT’s claim that the increased use of trains without guards, where the driver opens and closes the doors at stations, is a safety issue.
However, ScotRail has denied there is a safety issue and said almost 60 per cent of passengers travel on trains with doors operated by the driver. It also promised to ensure a second member of staff was on board to help the driver in emergencies.
Cancelled services have included those from Edinburgh to Dunbar, Aberdeen, Dyce and Inverurie.
Meanwhile, the number of services between Edinburgh and Glasgow have been further reduced. Conductors are due to walk out again this Sunday.