Motorists are facing a 24-mile detour as two historic Aberdeenshire bridges and a well-used tourist route close for three weeks.
The A939 Ballater to Tomintoul Road, along with Gairnshiel and Milton Bridges, will shut next month.
Aberdeenshire Council has warned the work could affect bus tour companies that operate along the route.
The road, which links Royal Deeside to Donside, will close from May 14 for three weeks, during which a combined diversion route will be in place via the A93 (Crathie, Ballater and Dinnet), A97 Dinnet to Donside and A944 through Strathdon to Colnabaichin.
The council has written to more than 20 bus tour companies to make them aware of the weight restriction, which currently only affects very large coaches.
The additional distance travelled when going between Braemar and Tomintoul will be 24 miles.
The Gairnshiel Bridge has withstood damage by large vehicles negotiating the sharp corner at the north end, and despite efforts to widen the approach to the north and partial rebuilding of the south end, it has continued to deteriorate and structural capacity continues to be an issue.
Damaged stonework will be taken down and rebuilt on both bridges and the Milton Bridge will be strengthened by the addition of concrete backing.
Repairs were also postponed due to the use of traditional lime mortar requiring suitable weather.
Aberdeenshire Council’s bridges manager Donald Macpherson said: “Carrying out repair of the two bridges in the same vicinity and at the same time, as well as any road repairs, is intended to minimise disruption for road users and the effect on tourists visiting the area.
“Hopefully this will also mean the road doesn’t have to be closed for repairs later in the year.
“Given this work has to take place in better weather, we’re doing it at the earliest opportunity, hopefully ensuring the road remains open in the peak summer season.”