Only major routes in Plymouth are being treated as gritting supplies begin to run low.
The city council said it was now prioritising which roads were gritted.
It said it was working closely with the emergency services and other organisations to keep vital services running in the city.
The council said that it normally had more than 750 tonnes of salt at the start of the winter but it had ordered an extra 200 tonnes this time.
Motorists have been urged to avoid any unnecessary journeys and to drive with extreme care when travelling.