Resurfacing work which started yesterday (Monday) means that the A814 on Loch Longside will be closed for four weeks.
Carried out by Argyll and Bute Council, the work means the road will closed from 8.30am to 4pm from Monday to Friday, until Friday July 11.
A diversion route along the A817 Haul Road through Glen Fruin and the A82 has been signposted, but there will still be access for properties at the north end (Arrochar) and the south end (Portincaple).
The authority is also planning work on the B833 which runs alongside the shore on the Rosneath Peninsula.
Maintenance and surface dressing work costing £120,000 will be done in two stages – on the approach to Clynder and then in Cove – and is scheduled to begin in October.