Drivers are being urged to prepare for plummeting temperatures bringing hazardous road conditions.
Police are advising people to make sure their vehicles are ready for winter before setting off on a journey.
Sergeant Mark Mitchell, from the Western Area Roads Policing Team, said drivers should keep warm clothing, a torch and a shovel in their cars.
And if the conditions look too severe to be driving in, then people should stay off the roads.
To make sure a vehicle is road-worthy, drivers should check lights are clean and working, the battery is fully charged, windscreen, wiper blades and other windows are clean and the washer bottle filled with screen wash.
Tyre condition, tread depth and pressure of all the tyres, including the spare, should also be checked, and drivers should ensure brakes are working well and fluids are kept topped up, especially windscreen wash, anti-freeze and oil.
Drivers are also advised to listen to local and national weather broadcasts and travel bulletins regularly as conditions can change rapidly.
Matthew Tomlinson, solicitor from the Road Traffic Accident department at Russell Jones and Walker, said their advice on staying safe and legal in the wintry weather includes clearing snow from the tops of cars.
He said it is not against the law to drive with snow on the roof of a car but clearing it before beginning a journey is common sense.
And he said if snow flies off your roof into the windscreen of another car, you could be penalised for driving without due consideration, dangerous driving, and not being in proper control of your vehicle, risking a fine of £60 and three penalty points.