The Highways Agency is advising drivers to take extra care on the roads, with the Met Office forecasting patches of dense freezing fog on some routes in northern England and the Midlands on Thursday morning.
The fog could be slow to clear and may linger into the afternoon on some roads on Thursday and Friday.
Roadusers should be extra cautious as visibility could change without warning.
Drivers are advised to use dipped headlights or fog lights if visibility is seriously reduced (less than 100m/328ft). Fog lights can dazzle other road users and obscure brake lights, so should be turned off immediately as visibility improves.
In patchy fog try not to speed up as visibility improves, as roadusers could suddenly find themselves back in thick fog further up the road.
It can feel more secure to 'hang on' to the tail-lights of the vehicle in front, but drivers should beware - it is a false sense of security. Travelling too close to vehicles is dangerous, particularly
when reduced visibility could obscure potential hazards and force a vehicle to stop abruptly.
The Highways Agency is advising drivers that the best way to stay safe on the roads during severe weather is to plan their journeys. Up-to-date information on road conditions on England's motorways and trunk roads is available on the Highways Agency website at www.highways.gov.uk, from the new Traffic Radio service on DAB digital radio or at www.trafficradio.org.uk, or by calling the Highways Agency 24-hour automated phone service on 08700 660 115.
For information on weather conditions, visit the Met Office website at www.metoffice.gov.uk or listen to local radio broadcasts.