An Adelaide man accused of hitting a toddler with his car did not stop to help the dying boy because he did not feel safe, a court has heard.
Michael Craig Bullock, 54, is on trial in the District Court over the crash, which killed two-year-old Zayne Colson in February 2017.
Bullock has pleaded not guilty to charges including aggravated driving without due care and failing to stop.
Opening the trial on Wednesday, prosecutor Rebecca Gray told the jury Zayne was playing outside his Dover Gardens home with his five and seven-year-old sisters when he was hit.
"He was dragged underneath the car for a few metres and was left lying in the road," she said.
"The accused, following the collision, immediately drove on to his home that was 100 metres away."
The jury heard it was Bullock's wife who contacted emergency services, but Bullock told the operator: "I didn't stop. It wasn't safe."
Ms Gray said there was nothing remarkable about the residential street that made it unsafe to stop.
"The prosecution case is that when the accused drove away, leaving Zayne Colson lying fatally injured in the middle of the road. The only people nearby were his two young sisters," she said.
But Angus Redford, for Bullock, said his client was not required to stop because he genuinely believed his safety was under threat.
Mr Redford said Bullock would dispute that his driving was careless.
"You might think that the law doesn't require a driver to have eyes in the back of his head," he told the jury.
"That if you are distracted by one person... you might just miss a little tacker, a two-year-old little fellow, running from the right-hand side of the road across your path."
The trial continues before Judge Paul Cuthbertson and a jury.