The Met Office has issued two yellow weather warnings for ice from central Scotland down to Manchester and in central southern England and southern Wales until midnight.
Many motorists have become stuck on busy roads with some vehicles being abandoned in the Central Belt.
Traffic Scotland reported that heavy snow overnight was affecting many routes on Friday morning, including the M77 and M74, and urged drivers to take extra care.
It said multiple vehicles were stuck on the M8 E/B offslip at J16 due to difficult driving conditions at around 6:40am and that gritters were on their way to the scene.
Bear North West Trunk Roads said there was snow on routes including the A82 in the Glencoe and Tyndrum area, the A9 and the A83.
Meanwhile, police in East Dunbartonshire tweeted: "Please take care if you need to head out in your car this morning.
"There are a number of vehicles abandoned throughout East Dunbartonshire due to the weather. Stay at home if you can, and travel later once the roads are a bit clearer."
Met Office forecaster Craig Snell said: “It has been a wintry 24 hours across a good chunk of the UK.”
He expected temperatures after sunset to drop low enough to cause icy conditions on untreated roads in the areas of the yellow weather warning.
But later in the night, air temperatures are forecast to rise again as a band of rain comes across, meaning the ice should have gone for most by Saturday morning.
The Met Office warning had covered the risk of icy patches on some untreated roads, pavements and cycle paths, and said snow showers were likely.
Morning commuters Scotland’s railways and roads in the affected area were urged to only travel if necessary.
A number of schools also faced disruption as a result of the weather.
In the Highlands, Grantown Grammar School and Kingussie High School were closed due to severe road conditions, while in Glasgow, St Margaret Mary's secondary school were sent home early because staff could not get into work.
In South Lanarkshire, which reported heavy snowfall overnight into Friday, the asymptomatic Covid test site at Larkhall Leisure Centre delayed its opening as a result of the winter weather.
East Ayrshire Police issued a warning of poor road conditions due to ice and snow around Galston, Stewarton and Dunlop and urged care when travelling, with reports of congestion across numerous routes.
North Ayrshire also issued a warning of freezing road temperature, with temperatures on roads expected to drop below zero, and gritters out in the authority from 3pm.
Bin collections across a number of councils were also delayed due to the adverse weather.
There was at least some joy to be had around the winter weather, with many parks busy with keen sledgers in many places.
And Bear Scotland sparked some delight on social media revealing the musical theme to their gritters ensuring Scotland’s roads were clear and safe amid the weather warnings.
Many of the gritter vehicles names on the roads in Scotland had musical puns, including Gritney Spears, Spready Mercury, Licence to Chill and I Want to Break Freeze.