Ontario's police watchdog has cleared Ottawa police of wrongdoing after a 34-year-old man was struck by a tractor-trailer while fleeing from an officer.

"The choices made by the [man] to flee from police, and then run into an active lane of traffic, were his own," said Special Investigations Unit director Tony Loparco in his report, released Wednesday. "Only he is responsible for the unfortunate results."

The incident happened in December 2016. Ottawa police patrolling on foot near the intersection of King Edward Avenue and Rideau Street smelled marijuana and decided to investigate a group of men after seeing one of them smoking.

While police were arresting one man, another fled on foot. One officer pursued the man, who entered the northbound lanes of King Edward Avenue where he was struck by a tractor-trailer.

The man sustained fractures to his left leg and was taken to hospital.

In his report, Loparco said it's clear there was no direct contact between the victim and any police officer, and that the complainant consciously decided to flee from police.

Loparco said while it's true the man may not have been injured had police not investigated the group, police officers "cannot be held accountable for the actions taken by persons who wish to evade them."

The SIU is an arms-length agency that investigates incidents involving police in which someone is killed, injured or accused of sexual assault.