As the winter weather bites, Halfords and the police are warning that drivers who fail to properly clear the snow off their cars could end up being prosecuted for careless or inconsiderate driving.
A fifth of motorists in the UK - almost six million people - don't remove the snow from their cars before heading off, according to research by the car parts retailer.
The study found that while most drivers make sure their windscreen, rear window and drive are clear of snow, many leave the car roof untouched.
However, if this snow was, for example, to slip on to the road and cause an accident or slide forwards and obscure their view, they could find themselves being prosecuted for careless or inconsiderate driving.
The police warned that there are many ways in which the snow could cause an accident and if it was deemed to be a factor in an incident, the driver could face much more serious consequences than the fixed penalty of three points and a £60 fine for driving with an obscured windscreen.
Experts at Halfords said that a heavy layer of snow on the roof also reduces a cars fuel efficiency.
They found that 4in of snow on the roof of an average sized car weighs around 35kg and could reduce fuel efficiency by about 2%.
Copyright Press Association 2013