The London-bound carriageway in Mountnessing, Essex, was blocked by a three-vehicle crash
A trunk road has been blocked by two separate crashes, one of which resulted in a tractor driver suffering life-threatening injuries.
The A12 was closed northbound in Bucklesham, Suffolk, following a crash between a tractor and a car just after 09:00 BST.
Suffolk Police said the drivers of both vehicles were taken to hospital.
The road was also blocked in Mountnessing, Essex, following a crash involving two cars and a motorbike.
Essex Fire and Rescue Service said three crews were at the scene on the London-bound carriageway, along with an air ambulance.
An Essex Police spokeswoman said the crash happened just before 12:00 BST and four people, whose injuries were not believed to be life threatening, had been taken to hospital.
