Contractors will begin the latest stage of the programme to reduce the risk of landslides on the route in Argyll and Bute.
Transport Scotland, the Government roads agency, has already spent £3.7 million on the project and the latest phase will bring the total spent on landslide debris mitigation measures to £4.9m since 2009.
A further £2.55m has gone on providing a local diversion route.
Next week's work will see additional debris netting put on slopes above the road. Two-way traffic signals will be in operation. During daytime hours, the traffic levels will be monitored and if necessary, the signals will be manually operated to reduce delays.
Eddie Ross, spokesman for the North West Unit of road firm BEAR Scotland, said: "We would like to thank drivers in advance for their patience when the work is being carried out and would ask them to allow extra time for travel."