Freezing fog and plummeting temperatures brought travel disruption to parts of the UK - and it's set to continue tonight.
Motorists were warned that roads could become "lethal" due to the hazardous combination of poor visibility and the onset of ice, the AA said.
Traffic was slow moving this morning in parts of the region due to the conditions and an incident on the A1 also caused gridlock.
The dual-carriageway was closed for several hours this morning after a lorry caught fire near Scotch Corner.
The full Met Office forecast for Yorkshire:
This Evening and Tonight:
Further dense and freezing fog patches are likely for a time overnight, but these tending to lift to mist and low cloud by morning as a breeze pick up. Minimum temperature -1C.
Milder and breezier on Friday, with some bright or sunny spells developing, especially across the east of the region. Maximum temperature 9C.
Outlook for Saturday to Monday:
Saturday windy with some bright spells in the east, but with rain moving south overnight. Sunday much colder with wintry showers, these confined to coastal areas on Monday.
Sub-zero temperatures swept across the UK on Thursday morning, with the mercury dipping to freezing levels in rural areas.
The Met Office issued a "yellow" fog warning for much of England, which said visibility could drop below 100 metres in some areas.
The AA urged "extreme caution" for those heading out on the roads, adding that extra time should be allowed, tyres properly inflated and screens adequately de-iced.
Spokesman Ian Crowder said: "We have got the worst possible conditions really, of fog and icy roads, and that can be lethal.
"I think the message is extreme caution and to prepare for the worst and make sure all windows are clear."
He added that failure to do so could "lead to disaster".
On Wednesday, Public Health England (PHE) issued advice for the over 65s, those with long-term illness or who are not mobile.
Dr Thomas Waite, consultant in extreme events and health protection at PHE, said: "The effects of cold can be severe, in particular for those who are over 65, have a long-term illness, or are not mobile. Our advice to these groups is when indoors, have plenty of warm food and drinks and try to maintain indoor temperatures to at least 18C.
"If mobility isn't an issue, keep active as best you can. If you need to go out wear lots of thin layers, and shoes with a good, slip-resistant grip to prevent any accidental falls. It is particularly cold at night this week, so drawing the curtains at dusk will keep the heat in."