A serious crash, believed to be a collision between a tanker and a motorcyclist at the roundabout at Carkeel, has closed the A38 with motorists being diverted to the Torpoint Ferry instead.
The road is shut eastbound at Trerulefoot and westbound at Carkeel.
Police are advising motorists not to use St Germans as a cut through.
In addition, the Saltash Tunnel is closed westbound and traffic is being diverted through the town centre.
More top news
Ashburton in Devon has become the first town in the UK to move its entire library into the local post office.
Find out which train services will be affected by the strike - and plan your bank holiday accordingly.
Bob Crampton warns that it will be showery and blustery over the next few days but the sunshine will still get a look in.