The A15 was closed in both directions following a serious collision at Northborough.
The road was shut between Maxey Road and Helpston Road following the collision, which happened on the southbound carriageway at 3.45pm.
A spokeswoman for Cambridgeshire police said all people involved in the crash were conscious and breathing, but one person had suffered ‘potentially serious injuries.’
Police, Cambridgeshire Fire and Rescue and the East of England Ambulance Service were all on the scene.
The road had reopened by 6pm.