The accident happened when David Blick was riding slightly ahead of Michael Anthony Franklin on the off-ramp from Capital Circle onto Canberra Avenue on their way home from work during peak hour one night in June, 2009.

Court documents said Mr Blick hit a large wooden tree stake lying in the bike lane and veered into his friend, causing him to fall off his bike and into the path of an oncoming car.

Mr Franklin, who was 43 at the time of the incident, recalled his friend's body slammed into him before he was thrown on to the road and the car ran over his back.

The victim suffered internal bleeding, grazes and serious fractures to his pelvis and spine which required the insertion of pins and screws to fix the damage.

Mr Franklin later returned to work part-time as an IT consultant but continued to experience serious flare-ups of chronic back pain and disrupted sleep, forcing him to work fewer hours.

He launched a civil negligence case against Mr Blick, who denied he was liable and said his only duty was to take "reasonable care" in the circumstances.

He said the fact he lost control of the bike because he hit the wooden stake did not mean he breached that duty.

But Justice John Burns disagreed and was satisfied Mr Blick breached his duty of care to Mr Franklin and that the man's injuries were a result of the defendant's negligence.

The judge ordered Mr Blick pay nearly $1.7 million compensation, taking into account a loss of future earnings and superannuation, plus legal costs.

Mr Blick appealed that decision on grounds the finding he breached his duty of care and caused Mr Franklin injuries and loss was based on inadequate evidence about flawed lighting, and that expert evidence was required to show he failed to exercise reasonable care.

He also argued the judge didn't properly explain his reasons for finding the accident was avoidable.

But a full bench of the ACT Court of Appeal this week found that none of the challenges to Justice Burns' finding were upheld.

The court found there was enough evidence to support the judge's finding that there was additional lighting in the area where the accident happened.

"In 2010, the appellant told an investigator he had good quality headlights which provided adequate lighting and he also said that there was a lot of vehicle lighting," court documents said.

The court also found that while expert evidence may have assisted the judge, it was not required and the lay evidence was sufficient for him to make his finding.

The appeal documents stated the critical issue at trial was whether Mr Blick did not see the wooden stake because he failed to keep a proper lookout, or because the stake was not clearly visible to a person keeping a lookout.

"The primary judge reached the obvious conclusion that the appellant failed to see the stake because he failed to keep a proper lookout.

"As avoidability was assumed and was not put in issue in the trial, it was open to his Honour to conclude that the appellant's breach of duty caused the respondent's injuries."

The court dismissed the appeal with costs.