Many buses in Sheffield are being sent back to the depot as icy conditions on the city's roads make it 'unsafe' for services to continue running.
First South Yorkshire announced at 9pm tonight that it had decided to remove most of its buses from the road briefly due to the treachesour condition.
It said a limited number of buses will run until the end of service tonight.
The operator said: "After today's snowfall, particularly on local estate roads and on higher ground, coupled to freezing temperatures, there have been significant impacts to local bus services. Most of these issues are the result of slippery road surfaces making it unsafe to run safely on the road network.
"Accordingly, we have taken the decision to remove most of our vehicles from the road briefly to enable reformation of services and to get buses back in position and enable gritters the chance to cover as much of the network as possible.
"An update will be provided shortly advising customers of journeys and routes to be provided to the end of daily service.
"Whilst we appreciate that this is difficult for some customers, it is important to balance the safe movement of our customers, staff and vehicles and to provide key services as far as possible.
"If you are travelling, please remember to take extra care on untreated surfaces such as pavements, wrap up warm and leave a little extra time for your journeys."
From 9.30pm until the end of service, the following services will be running on a basic 30-minute frequency using only main roads (ie not going into local estates where road conditions are most challenging):
1a Olive Grove to Sheffield Lane Top
20 City to Ecclesfield
24 Woodhouse to Low Edges
52a Woodhouse to Hillsborough
75 Norton to Firth Park
76 Low Edges to Firth Park
81 Malin Bridge to Ecclesall
120 Ranmoor to Crystal Peaks
X1 Sheffield to Maltby
X5 Sheffield to Dinnington
X78 Sheffield to Rotherham to Doncaster