The Highway Agency's operations director has warned drivers to think very carefully before venturing out.

Derek Turner said the country had been hit by a "huge dump of snow" and drivers who do brave the elements should be well prepared for the journey by taking with them warm clothes, a hot drink and a shovel.

His comments come as the emergency services admit that the extreme weather caught them out. Both the AA and the RAC have had to cope with vastly increased demand. Paul Watters of the AA admitted: "We really have been caught napping. Thirty years ago, local authorities had direct labour organisations, which meant they could mobilise huge armies of people. Now it is all done by contractors. We need to find a way of throwing the switch, so we can get these armies of people out there again."

He said that it was unacceptable in the 21st century to have people trapped in their cars and lorries on motorways for hours at a time.

Meanwhile North Yorkshire Police has issued a warning to drivers about snow being left on cars when they drive off. The force said in a statement: "If it slips over the windscreen, or flies into the path of another car, it could leave the driver open to being penalised for driving without due care and attention or careless or inconsiderate driving." It warned that snow could slide onto lights or windows obstructing vision or signals to other road users.