Tyre marks at the scene and comments from another local resident indicated the man was driving uphill when the crash happened.
He smashed into a fence, taking out a tree along the way, and was wedged against the fence with timber pinning his head down, and another piece of timber impaled in his side, a witness said.
Discussing the actions of the residents who went to help the injured man, St John Ambulance said "a few simple measures can help save a life".
St John Medical Director Dr Tony Smith had the following advice for anybody who found themselves in a similar position:
Ensure the scene is safe, for example park to protect the scene if necessary.
Dial 111 if anyone appears injured. Ensure you know exactly where you are before you call. Don't dial 111 just because you have seen a crash, for example it is not uncommon for people to dial 111 for nose to tail crashes on the motorway where nobody is injured and this unnecessarily 'ties up' an ambulance.
Do not move a person unless they are in immediate danger, noting that it is OK to allow people that appear uninjured to move themselves.
If a person is unconscious, ensure they have an open airway by tilting their head back and lifting their chin. This is more important than not moving their neck. An unconscious person may block their airway -- and if this is the case they may have breathing that sounds like they are snoring.
Stop external bleeding by pushing firmly on the site of bleeding using a clean cloth like a towel or a T-shirt.
Keep people warm, for example by putting a blanket on them.
Dr Smith said it was extremely rare for a patient to be impaled on an object and most will never encounter such a situation. If this happens, do not move - or remove - the object and wait for ambulance staff to arrive.
