Wiltshire Air Ambulance airlifted a man to hospital after a pole became wedged in his car during the early hours of the morning.
Police were called just before 12.45am to the B4040 at Charlton by the ambulance service.
A Honda Jazz, driven by a 45-year-old man from the Malmesbury area, had hit a metal barrier alongside a stream, a pole becoming stuck in the car.
The man, who suffered leg injuries in the incident, was taken to Frenchay Hospital, near Bristol, by the air ambulance.
He told police another car had forced him to swerve from the road.
Road closures were put in place during the night between Stonehill Wood and Perry Green and were reopened at about 6am.