Dylan Wolter, 22, has been on trial in the ACT Supreme Court this week for killing Natalie Ashley, 80, as she crossed Mawson Drive in August 2013.

Mrs Ashley usually crossed the road to return home from painting at the family's nearby art studio, and her family said she was extremely careful when doing so.

Walter was allegedly speeding, had ice in his system, and was close to the gutter.

He has pleaded not guilty to a charge of culpable driving causing death.

Wolter said he did not see Mrs Ashley before the collision, and the jury have been told that the sun caused glare due to its position in the sky at that time of year.

Wolter's barrister James Sabharwal told the jury that they would all have felt sympathy for Mrs Ashley's family and their loss.

But he warned them against allowing emotion to interfere with the way they viewed the case, saying they must make their decision "coldly and dispassionately".

He attacked the credibility of a doctor who gave evidence about the possible effects of ice on Wolter and his driving, and told the jury they should find the drug had not impaired him.

Mr Sabharwal said the stretch of Mawson Drive involved was usually travelled at fast speeds by motorists.

He said the prosecution had failed to prove the charge of culpable driving.

"You cannot be satisfied of that very high standard of negligence that's alleged against him," he said.

But prosecutor Trent Hickey told the jury that it was "simply unfathomable" that Wolter had not seen the pedestrian before the crash.

He said Wolter had a clear line of sight, and that two drivers who arrived at the scene after the crash had clearly seen Mrs Ashley's body on the road.

"It is simply inexplicable that the accused didn't see her," he said.

He alleged Wolter had been driving aggressively, cutting a corner near a gutter, something Mr Hickey linked to the near-toxic level of ice found in his system.

Justice Richard Refshauge will deliver his summing up to the jury on Friday morning.