Snow showers are continuing to affect roads across the borough on Thursday.
And there is also the risk of ice on untreated roads especially in rural areas.
A Met Office amber warning of snow remains in place, valid until 11:00 GMT on Thursday, with some morning rush-hour disruption expected.
Transport NI, formerly known as Roads Service, said that strong winds are also likely to combine with the snow to make conditions more difficult.
It said salting and ploughing operations are continuing.
Police have advised drivers to slow down, put their lights on, leave more room to stop than usual and brake gently to avoid skidding.
“Drive slowly on snow in the highest gear possible,” a PSNI statement said.
“Do not assume your vehicle can handle all conditions. Even four-wheel drive vehicles can encounter trouble on winter roads,” it added.
Places in the south east of Northern Ireland that do not have much snow will still be bitterly cold and will be at risk of ice, forecasters have said.
The cold weather will continue throughout Thursday and it will remain very cold until the beginning of next week.