Four Elms Hill is blocked in both directions following an accident.
Recovery works are underway following an incident involving a Hyundai and Nissan.
A police spokesman said a car had flipped and landed on its roof but there were no serious injuries.
Diversions are in place while recovery works get underway to move the vehicles and clear oil spilt on the road.
A police spokesman said: "Two vehicles were involved, one has flipped and landed on its roof. There is no serious injury. Road closed both directions for recovery and diversions in place. Highways has been informed due to oil on the road. The road should reopen once recovery completed."
The road has been closed since the middle afternoon with traffic building in the local area.
The police traffic website said: "The A3052 Four Elms Hill both ways blocked, queuing traffic due to accident from Higher Way (Newton Poppleford) to Back Lane (Bowd)."
More to follow.
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