Three people, including two police detectives, were injured when two cars collided on Picton Road on Wednesday.
The officers were heading east in an unmarked vehicle when they were hit from behind by another car at Cataract about 11am.
The police car rolled a number of times, leaving the two officers with minor injuries. The man driving the other car suffered major head and chest injuries.
Emergency services freed him from the wreckage before he was flown to St George Hospital, where he was in a critical but stable condition on Wednesday night.
The road was partially closed due to the crash.
The speed limit on Picton Road was returned to 100km/h this week for the first time in four years after being reduced to 90km/h in 2009, when Roads and Maritime Services began safety improvements on the road.