Senior SA cop avoids discipline over crash

A high-ranking South Australian police officer will not face disciplinary action after causing a road crash that seriously injured a motorcyclist.

SA Police Commissioner Grant Stevens says he won't take disciplinary action against Assistant Commissioner Philip Newitt, who was last month convicted, fined and handed a six-month driving ban over the 2015 crash.

"I determined the penalty imposed by the magistrate was sufficient and proportionate," Mr Stevens said in a statement on Thursday.

Mr Newitt could have faced a range of penalties - counselling, a fine or the loss of his job.

In full reasons for his decision Mr Stevens said he had considered having the matter determined by another officer because of having known Mr Newitt for about 20 years and socialising with him on occasions.

"However, I believe that my clear and unambiguous role as the commissioner of police must be performed without fear or favour," he said.

In August, Mr Newitt pleaded guilty to one count of aggravated driving without due care over the crash in the Adelaide Hills on December 28, 2015.

He was off duty at the time and driving his own car at Cudlee Creek when he came to an intersection and entered to turn onto another road.

He had driven his vehicle partially into the oncoming lane before seeing the motorcyclist coming in the opposition direction.

The rider hit Mr Newitt's vehicle, suffering fractures to an arm and cheekbones and spent six days in hospital.

Mr Stevens said at the time of the crash the assistant commissioner immediately stopped his vehicle, rendered assistance and called triple zero.

He said speed was not a factor, nor was Mr Newitt under the influence of drugs or alcohol and his actions had not caused any harm to the reputation of the police force.

"Having stated my observations and considerations, I find that you have acted professionally and responsibly at all times from the moment of the collision," Mr Stevens said.