Arctic air sweeping across Scotland has brought extremely low temperatures, snow and ice to much of the country.
An extended yellow weather warning from the Met Office is in force with concern that dangerous conditions could cause disruption and injuries.
This week is expected to be the coldest in December in Scotland for nearly a decade, with lows of -10C in some areas.
All of Scotland north of the Isle of Mull and Fort William in the west and Montrose in the east is affected by a snow and ice warning in force from midnight on Thursday until midday on Friday.
From 4pm, an ice warning covers Scotland southwards from Ayr, lanark and east of Edinburgh.
Amey South West Trunk Roads announced that 28 gritters and 15 patrol gritter vehicles would be out overnight treating the network.
STV meteorologist Sean Batty said it was shaping up to be a significant spell of severe cold conditions, and some areas could experience their coldest December weather for several years.
He said overnight temperatures may drop as low as -7C in Lanarkshire, Glasgow and Renfrewshire at the weekend, which would make it the coldest December conditions since 2017 when Bishopton hit a low of -8C.