A full 1km section of the Maybole Bypass is to be constructed below ground level as it passes the north of the South Ayrshire town.
The move comes following comments received after a public consultation. The enhancements will help screen the bypass from nearby homes.
In addition the northern section of the new road will be slightly realigned to reduce the impact of the route on farmers’ fields.
Transport Minister Keith Brown said, “Constructing a bypass at Maybole will help separate local traffic from traffic travelling further afield, including to the ports. This will lead to improved road safety for local communities and road users alike and provide better journey time reliability for motorists and businesses along the full length of the A77.
“I am only too aware of the impacts of constructing a road near a rural community such as Maybole.”