The A66 trans-Pennine route between Bowes, County Durham, and Brough in Cumbria, is now expected to remain closed until at least noon tomorrow, according to the Highways Agency.
Durham Police tonight confirmed that the route will remain closed overnight.
Earlier this afternoon the forced urged people not to travel to Upper Teesdale or Weardale unless their jolurney is absolutely necessary.
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"Road conditions are hazardous following heavy snow overnight which due to windy conditions is blowing back onto road surfaces making many minor roads in Upper Teesdale and Weardale impassable," a spokesman said.
The issued the appeal after dealing with a number of motorists who had become stranded.
Cumbria was one of the worst hit areas and upto 70 people had to be rescued from cars and lorries which became stuck in snowdrifts up to 15ft high last night on the A595 and stayed overnight in Millom.
Snow drifts closed many roads in the area, with others - including the M6 between Hackthorpe and Shap - only passable with care.
This morning Electricity North West is still trying to restore power to parts of Cumbria, with more than 300 customers still without electricity.
In Scotland, ScottishPower estimated there were some 6,000 homes still off supply in the south-west area.
Drivers of high-sided vehicles using the A19 flyover on Teesside are being advised to take extra caution due to high winds while Durham County Council is warning people to take care in the Low and High Pennines today due to strong winds and drifting snow.
Forecaster Chris Burton of MeteoGroup, said: "Most places have seen some kind of snow, with the highest levels in the Peak District and the Pennines.
"Strong easterly winds have have been blowing the snow around on higher ground, causing snow drifts and reduced visibility. In some areas, snow is drifting in excess of a metre."
The highest recorded snowfall so far was Bingley, West Yorkshire, with 22cm (8.6 inches) but some parts of north-east Wales are thought to have seen up to 30 cm (11.8 inches) of snow.
In lower-lying regions, up to 5cm (two inches) of snow have fallen.
Mr Burton said that temperatures will only be just above freezing during the day with widespread frost overnight, with temperatures down to minus 3C.
Heavy snowfall forced the closure of runways at East Midlands Airport, with no aircraft able to fly in or out.
Humberside Airport has been closed since 8am, with no flights landing or taking off at Leeds Bradford Airport either.
Doncaster's Robin Hood Airport closed for a short time, later reopening with limited service.
DFDS Seaways say that due to bad weather conditions, its outbound crossing from Newcastle to Amsterdam will depart early from North Shields today (Saturday 23 March) at 3pm.
Cruise ferry Princess Seaways, due to arrive at 9.30am in Ijmuiden, Amsterdam today has been delayed and is now due to arrive in port at 8pm.
The following crossings have been cancelled: inbound from Ijmuiden, Amsterdam to Newcastle – Saturday 23 March and outbound from Newcastle to Ijmuiden, Amsterdam – Sunday 24 March.
Sports fixtures also fell foul of the weather, with international and domestic football programmes hit.
Northern Irelands World Cup qualifier against Russia was called off for the second time in 24 hours, with hostile conditions making Windsor Park unplayable.
Other cancelled games included Sheffield United's npower League One clash against Brentford and Shrewsbury's meeting with Oldham.
In League Two, the games at Rotherham (v Exeter), Burton (v Wycombe), Chesterfield (v Plymouth), Crawley (v Crewe), Port Vale (v Aldershot) and Rochdale (v Southend) all went the same way.
Games between Elgin and Clyde, and Annan and Queens Park, were cancelled in Scotland.
Race meetings in Doncaster and Newbury were also abandoned due to snow.