Gairnshiel Bridge, near Ballater, was built between 1748 and 1752 as part of the Hanoverian military road network.
Now, a new bridge is to be built over the River Gairn to ease pressure on the narrow structure, which has been weakened by a number of collisions over time.
It has yet to be decided whether the Grade A-listed bridge will be close to traffic altogether once a new crossing has been built a short distance to the east.
Councillor Peter Argyle, chair of Aberdeenshire Council’s Infrastructure Services Committee and local ward member, said: “It’s clear that action needs to be taken both to protect the beautiful and historic Gairnshiel Bridge and to make the route more accessible for modern traffic.
“There is still much to be done to develop formal plans and conduct the necessary consultation with interested parties but the principle of a new crossing would seem to be the most sensible way forward.”
The bridge carries the A939 over the River Gairn, around six miles north of Ballater, providing a vital road link between the Upper Deeside and Upper Donside Valleys, then further north to Tomintoul in Moray and on to Speyside.
Historic Environment Scotland said the crossing was an “excellent example” of a military road bridge, built on the Military Road from Blairgowrie to Fort George which was completed in 1749.
Following the major unrest of Jacobite attacks and the battle of Culloden, the Government began a sequence of road building in the Highlands under General Wade to allow better communications between the Government troops.
The Blairgowrie to Fort George Road was established by his successor, William Caulfield.
The bridge has suffered the effects of modern traffic, with a sharp turn at its northern access proving difficult for larger vehicles. There have been several collisions with the bridge parapets, most recently just a day after reopening after repairs, and a weight restriction of 18tonnes was imposed in 2016.
Aberdeenshire Council plans to submit a planning pre-application to the Cairngorms National Park Authority later this year.
A detailed design will be prepared and, subject to planning permission, it is hoped the new bridge will be built 2021. Plans will also be drawn up for renovation of the existing bridge in 2022.