Police are advising any affected drivers to stay with their vehicle and to keep as warm as possible until help arrives.
Highways England gritter trucks have since treated the A30 at Bodmin to get traffic moving and to reach motorists who have been stranded for several hours. Vehicles were also stuck on the A39 in Cornwall and rescue vehicles worked their way inwards from Winnards Perch and Wadebridge to reach them.
Police were also aware of vehicles stranded on the A390 in Cornwall and are working with partner agencies to get the route clear and assist drivers.
The Met Office amber weather warning for snow and ice remains in place throughout today (Friday) and affects large parts of Devon and Cornwall.
Devon and Cornwall Police has issued strong advice to motorists not to travel and to be aware that conditions on roads – particularly on untreated routes – are likely to be treacherous.
Chief Inspector Adrian Leisk, Head of Roads Policing, said: “Please can all road users reduce their speed, give extra breaking distance between them and the vehicle in front, and if you must travel, leave both extra time for your journey and prepare for the worst – ensure you have a full tank, food and water in the vehicle, shovel and stop signs, a fully charged phone and warm clothing; all the things to prepare you in case of a breakdown."
For the latest on the weather, please see the Met Office weather warning webpage: www.metoffice.gov.uk/public/weather/warnings for the latest on roads affected, please see the Traffic watch website on www.devon-cornwall.police.uk/news/traffic-watch.