Police have reopened the A27 near Middle Farm, Firle, after a collision.
The driver, who is believed to have suffered what police describe as “a medical episode”, was in collision with a car coming in the opposite direction before driving into a ditch.
South East Coast Ambulance Service attended along with West Sussex Fire & Rescue Service.
The man was cut from the car and taken to the Royal Sussex County Hospital, Brighton, to be checked over. He did not receive any injuries.
The four people in the other car involved were not injured.
Sussex Police have thanked for their patience after the road was closed following the accident at around 3pm this afternoon when diversions were set up.