Motorists are being warned to expect disruption as heavy rain caused material to wash onto the A83 in Argyll and Bute.
The Old Military Road was shut in both directions at midnight by safety teams after ‘material’ was spotted on the carriageway.
Engineers will examine the scene at first light to determine the full extent of any damage on the trunk road.
But travellers are being told to allow extra time for their journey and to follow the signposted diversion via the A82/A85/A819 which is an additional 58.8 miles.
The A83 Rest and Be Thankful road has also been closed while heavy rain battered the region after being blighted by massive landslides in recent weeks.
Traffic Scotland tweeted: “A83 Rest and Be Thankful Old Military Road has been closed due to material on road following heavy rain.
Bear Scotland added: “Situation will be reviewed at first light.”
