Police Scotland advised only emergency workers should travel after bad weather left “many drivers trapped in vehicles for long periods”.
Extreme weather left drivers stranded and more roads impassable overnight - with another day of sub-zero temperatures, icy blasts and “blizzard-like” conditions to come.
Storm Emma, rolling in from the Atlantic, looks poised to meet the Beast from the East’s chilly Russia air - causing further widespread snowfall and bitter temperatures.
As winds picked up overnight, drifting snow caused misery for many motorists - with some parts recording accumulations up to a foot deep.
Motorists on the M80 near Glasgow reported being stuck for up to 13 hours, with some spending the night in their cars, and others abandoning their vehicles on the motorway.
The force tweeted: “Todays advice: don’t travel unless you’re an emergency worker. #REDALERT remains till 10am and at best will reduce to Yellow.
“Many drivers trapped in vehicles for long periods. Public transport disruption all day check @trafficscotland @ScotRail and radio for updates”