Extreme weather left road users stranded on a motorway until the early hours, with reports of some abandoning their vehicles.
Traffic became stationary on the M80 on Wednesday afternoon when heavy snow hit, with forecasters issuing the highest level warning for parts of central Scotland.
Motorists were prepared for a night inside their vehicles and it was not until around 1.30am that Bear Scotland said traffic was moving “slowly” in both directions, however conditions remained difficult.
Graeme Murray left Aberdeen at 2.45pm with his daughter Ella, 16, who was hoping to catch a flight to Dublin from Glasgow for an under-17s netball competition.
Graeme and Ella Murray had been trying to make it to Glasgow Airport before getting stuck on the M80 (PA)
Speaking at around 10pm, the 49-year-old legal commercial director said: “Everything was going well until just after Gleneagles, then we hit the traffic jam at 5.05pm and have been here ever since.
“We have no idea what’s happening, we’re just getting messages from home.
“I think we’re going to get ready to spend the night here.”
Mr Murray said there had been people from the local area who had been walking up and down the motorway offering chocolate biscuits and hot drinks.
He added: “That was very welcome.”
Police Scotland tweeted advice to avoid the route, while also telling people not to abandon their vehicles.
Other major roads also faced disruption, with the M74 being reduced to one lane heading north and south late on Wednesday.
Mountain rescue teams were drafted in to help emergency services deal with the overnight operation.
Met Office forecasters issued alerts across most of Scotland, with the highest level warning continuing until 10am on Thursday in central regions.
It is the first red alert for snow in Scotland since a new warning system came into place in 2011.
The definition of such a warning is “you should take action now to keep yourself and others safe from the impact of the weather” and it cautions that widespread damage, disruption and risk to life is likely.
Forecasters warned that lying snow could reach 40cm in a few places by mid-morning.
Lower alerts for snow and ice will continue to cover much of the country throughout the day.
Councils up and down the country have decided to close schools on Thursday due to the weather.
Major Scottish airports saw many flights cancelled, including Glasgow which halted all routes until 11am on Thursday.
However, British Red Cross emergency response volunteers were at the airport supplying bedding for up to 100 people in case they were stranded overnight.
The extreme whether has also seen NHS Greater Glasgow and Clyde cancel all non-essential operations and outpatient appointments on Thursday.
Virgin Trains has closed all its routes to and from Scotland throughout the day, while ScotRail halted all operations in the affected red area until late morning.
Bus operators in central regions also reported there would likely be disruptions continuing on Thursday.