A83 landslide: Weather hampers Rest And Be Thankful work
Bad weather has severely hampered efforts to assess the landslide which has closed the A83 at the Rest And Be Thankful.
The risk of further slips forced the closure of the road early on Thursday.
The Old Military Road diversion has been operating during daylight hours and a fallen power cable which added to problems on Saturday has been fixed.
Overnight, between 18:30 and 07:00, the usual 60-mile diversion will be in place, via the A82, A85 and A819.
Road operator BEAR Scotland said the severe weather on Saturday had stopped engineers assessing the risks of loose material and making safe boulders.
Specialist equipment remains on site ready to be airlifted up to the hillside as soon as this can be done safely.
A BEAR Scotland spokeswoman added: "Use of the Old Military Road local diversion route has again been a success, keeping traffic flowing under a traffic signal convoy system, and keeping Argyll open for business.
"As the hillside cannot be monitored in darkness, and the risk considered unacceptable to road users and their safety, it has again been agreed with Transport Scotland that given the difficulty in monitoring the slope during darkness the A83 will remain closed overnight."
BEAR Scotland added that it was hoped that better weather on Sunday would allow a helicopter to airlift equipment to the site of boulders on the hillside.
The spokeswoman added: "At this stage it is anticipated that this will take two days to complete. It is expected that the operation of the Old Military Road will continue in a similar pattern throughout this period."
The Old Military Road diversion was abandoned for several hours on Saturday after a fallen power cable shut the A83 at Cairndow.