Motorists are facing difficult driving conditions as heavy snow falls in some parts of the country.
The Met Office has issued a yellow warning of snow and ice for northern and north-west Scotland, which is in force until 10am on Wednesday.
A separate yellow warning of ice – which covers southern Scotland, much of England and Northern Ireland – is in place until 10am on Monday.
Traffic Scotland said there were reports of several vehicles becoming stuck in snow on the A835 between Ullapool and Braemore late on Sunday afternoon and urged people to take care.
There were reports of heavy snow on the A835 at Braemore and the A9 at Ord Ousdale, and gritters have been deployed in the area.
Network Rail Scotland said that snow and ice can build up on the tracks and result in trains being delayed or cancelled – and advised people to check ahead of their journey.
The Met Office said that frequent wintry showers, mainly of snow, will feed into northern Scotland during the period covered by the snow and ice warning.
It said: “A few centimetres of snow are likely at low levels over a given 24-hour period, with the potential for 10-15 cm above 200 metres, especially across parts of the Highlands.
“Ice will be additional hazard, especially Tuesday night.”
The snow and ice warning covers Moray, the Highlands and Western Isles, Orkney and Shetland and Argyll and Bute.