UPDATE 10.58am: Devon and Cornwall Police say that the westbound A30 at Kennards House, Launceston, is likely to be closed for another two hours.
The westbound carriageway of the A30 has been closed at Kennards House following a serious road traffic collision this morning.
The collision took place near to Two Bridges, Launceston, at around 8.10am and involved a single vehicle.
A car left the road and collided with trees.
The driver has sustained serious injuries.
It is thought that the road may be closed for some time and drivers are urged to avoid the area if at all possible.
Fire crews are in attendance.