The Met Office has issued a yellow warning for icy conditions across the Highlands and Islands for tonight and tomorrow morning.
As temperatures fall below zero this evening and Friday morning, icy stretches are likely to form on any untreated routes and there is the potential for some snow falling on highest routes.
The police said drivers should check the weather forecast and be aware of possible difficult travel conditions.
Up-to-date information road conditions can be obtained from the Traffic Scotland helpline on 0800 028 1414 or the website at www.trafficscotland.org.
Up to date weather information can be obtained at the Met Office website at www.metoffice.gov.uk.