Update 8.50am: Police are at the scene of a broken down fuel tanker on the southbound lane of the A338 between Launceston and Callington.
Traffic is queuing and drivers should expect delays.
A broken down articulated lorry is partially blocking a Roche road.
Both directions of the B3274 Victoria Road between Rock View Parc junction and the A30 are blocked.
Drivers should also be aware of hazardous driving conditions on the A30 in St Columb Road around Indian Queens because of fog.
There are also warnings of hazardous driving conditions on the A30 between Temple and and Carminow Cross in Lanhydrock House.