Drivers in Highland Perthshire are being warned of overnight road closures that will mean a diversion of around 34 miles.
From Saturday the B847 will be closed between Calvine and Struan from 10pm to 6am.
During these times, traffic will have to take an alternative route via Tummel Bridge and Killiecrankie.
Perth & Kinross Council has suggested the 34-mile diversion route, which will follow the B847, B846, B8019, B8079 and B847.
However, a shorter route is possible via an unmarked road.
But this will still see drivers diverted by at least 30 miles.
The closures near Blair Atholl will be in place until February 28 and will form part of a £1.25 million project that began in December.
Network Rail carrying out repairs on 161-year-old Perthshire viaduct
Network Rail is undertaking repairs on the Garry Viaduct, which carries the Highland Main Line across the River Garry.
Masonry repairs are being carried out to strengthen the 161-year-old viaduct.
Andy McManus, Network Rail scheme project manager, said: “The work at Garry Viaduct is essential so we can maintain the structure and keep services on the Highland Main Line safe and reliable.
“We’re investing millions in the Highland Main Line this year, including a £3 million bridge replacement project at Killiecrankie.
“The 140-year-old bridge over the railway was recently demolished, with a new bridge now in position.
“Work will be completed there in March 2025.
“We understand the impact this work is having on those living near Garry Viaduct and we thank the community for their patience whilst we carry out this vital project.”
Network Rail’s four-month-long programme of works on the viaduct is scheduled to finish on April 25.
More information is available from Network Rail’s 24-hour national helpline and on its X page.
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