The A27 is partially closed near Angmering after a car crashed into a field.
Sussex Police said it was called to the A27 in Patching at 12.24pm to reports a vehicle had come off the westbound carriageway and crashed into a field.
Police said two people were in the car at the time, but both were out of the vehicles - although there were reports of injuries.
The westbound carriageway has been closed by police while recovery vehicles get to the scene.
At this point, a police spokesman said it was likely that the westbound carriageway would be completely closed while the vehicle was retrieved.