Police Scotland have advised people to return home early in the areas affected by an upgraded weather warning.
They said they expect the worst of the weather to impact from about 3pm.
The Met Office upgraded its weather warning to amber for snow and ice, covering much of Scotland.
The “be prepared” alert is in place for wide parts of the country, including Strathclyde, Central, the Lothians, south west Scotland, Tayside and Fife from 07:00 until 22:00.
Police Scotland earlier increased its travel warning from stage 2 to stage 3, meaning travellers are likely to experience significant delays.
Supt Louise Blakelock said: “As we progress into this afternoon and evening, I would like to remind the public of the ongoing risk of disruption due to the forecast.
“If you travel on the road network in the warning area, you will be disrupted and you will face significant delays.
“With that in mind I would urge the public to think and plan ahead for their return journey home this afternoon.
“If you are able to, please make your homeward journey earlier. If you are an employer, please think carefully about allowing your staff to return home early if possible.”
She added: “Please ensure you are checking the most up to date information from Traffic Scotland and the Met Office.”
Transport Minister Humza Yousaf has warned people to think carefully before setting off.
He said: “If you choose to travel, particularly in the evening peak period, you are likely to face significant delays and disruption.
“Consider if you can make your journey home from work earlier than usual.
“Scottish government officials are contacting business groups to make them aware of this advice, and I’d also ask employers to be flexible and consider letting staff leave early.”
South Lanarkshire and North Lanarkshire councils closed all schools at lunchtime. Schools in Clackmannanshire also shut early.
In the Highland Council area four secondaries, 18 primaries and four nurseries continue to be affected by the wintry weather.
The schools are either closed or have school transport issues meaning pupils from rural areas have not been able to get a bus or taxi to school.
More than 1,700 pupils are involved.