Drivers are facing a 55-mile diversion with the closure of one of Scotland's busiest roads for 12 days of maintenance.
The trunk road between Tarbet and Crianlarich has been shut, creating problems on the A82 near Loch Lomond.
A crash barrier damaged in a lorry crash in May will be replaced during the £1m works.
Part of the road will be resurfaced, drainage works carried out, signage replaced, and vegetation cut back.
Construction firm Bear Scotland said it has invited other organisations to make full use of the road closure.
Teams from 12 different contractors will be involved in the maintenance work, which also includes removing unstable walls and bridge repairs.
A group from Argyll and Bute Council will carry out litter picking and Forestry Commission Scotland will undertake tree felling on land next to the road.
A total of 90 people in various different teams are expected to work on the road during its closure.
It will be shut to traffic between 08:00 and 18:00, from Monday to Friday, until Tuesday 21 November.
Local residents, businesses, emergency services, school buses and service buses will be able to gain access to places between the closure points.
All other traffic will be diverted via the A83, A819 and A85.
Eddie Ross, of BEAR Scotland, said: "Trunk road safety is our top priority, and in this case we have to close the road for the protection of our teams as well as motorists.
"We'll be sharing daily updates online about our progress on site, and we encourage all road users to plan their journeys in advance by checking the Traffic Scotland website for up to date information."