Blizzards and black ice today caused severe travel disruption in central and south-west parts of the country.
Dumfries and Galloway as well as Perthshire were worst hit overnight, after an amber "be prepared" weather warning was issued by the Met Office, and this morning there was a spate of minor accidents across those regions.
Police in Dumfries and Galloway issued warnings to motorists urging them not to travel on the M74 motorway, the A75 between Dumfries and Annan and all minor roads due to "completely treacherous" conditions.
In Perthshire, widespread black ice caused problems and there were "a lot of accidents" throughout the area.
Police said a lorry carrying bitumen fuel had been hit by a fire at 4.30am on the A90 at Kinfauns, causing severe disruption for commuter traffic.
Black ice was believed to have caused accidents on the M90 at Kinross and the A94 at Perth aerodrome, where a car had overturned.
Sergeant Robin Ferguson, from Dumfries and Galloway Police, said: "Road conditions on the M74 motorway are completely treacherous. The general advice at the moment is avoid travelling on that road. North-bound it is completely blocked due to a jack-knifed lorry. Visibility is very poor as the snow continues to fall.
"The A75 between Dumfries and Annan also has a warning of not to travel on the road. There are a number of LGVs stuck in that area and tailbacks are about four or five miles long with congestion in the east of the region at a standstill.
"All minor roads have not been treated and we would advise people not to travel on them. The rest of the A75 and other A-class routes are passable with care.
"The A701 due to two minor injury road traffic collisions, there is travel disruption on that road as well."
Last night, temperatures dropped to minus 2C across the central belt and the lowest temperature recorded was minus 3C in Caithness, according to forecasters.
The wintry showers which brought snow to the west of Scotland and over higher ground is expected to push east today.
Sean Penston, a forecaster for MeteoGroup, the weather division of the Press Association, said: "A heavier band of showers turning to snow will separate across Scotland heading south east towards the central belt. That will continue through the day and there will be more scattered and isolated wintery outbreaks following in behind.
"There will be strong winds causing the drifting of snow in some parts which could be quick dangerous."
On higher ground snowfall could accumulate to as much as 12-15cm, while on lower ground and central areas snow will range between a dusting of light snow to 3cm, he said.
Mr Penston added: "Into tonight there will be more sleet and snow on the way in eastern parts over higher ground.
"The wind is going to shift from a north-westerly to towards a north-easterly and more sheltered areas will be hit with showers."
The Met Office has reduced its snow warning for all regions of Scotland to yellow "be aware", which remains in place until 3pm today.
Information on driving in difficult conditions is available at: www.transportscotland.gov.uk.