The controversial camera system will operated between Beasley Street in Mawson and Drakeford Drive in Tuggeranong.

Point-to-point speed cameras already operate on Hindmarsh Drive.

ACT Attorney-General Simon Corbell said national statistics had identified speeding as a major factor in about 30 per cent of crashes.

"ACT crash data shows there were 568 crashes on the Athllon Drive corridor from Beasley Street to Drakeford Drive, including crashes at the intersections with those roads, between 2008 and 2012," Mr Corbell said.

"This included 40 crashes where people were injured."

The camera sites were chosen based on a forward design study and advice from an independent engineering consultant, who applied a 50:50 weighting of safety and traffic factors

The system catches speeding drivers by recording the time when they enter and leave a stretch of road to determine an average speed.

Early testing of the Athllon Drive cameras, which cover a 3.8-kilometre stretch of road, detected some high speeds.

One driver was travelling northbound at an average speed of 116km/h and another was travelling southbound at an average 103km/h.

The speed limit is 80km/h.

NRMA director Alan Evans has expressed concern about the placement of point-to-point cameras on Athllon Drive.

Mr Evans said the presence of the cameras could cause drivers to slow down at main roundabouts and then fail to drive to conditions as they sought to maintain an average speed.

Mr Evans said with two main roundabouts on the stretch between Drakeford Drive and Beasley Street, the presence of cameras see drivers slow down at roundabouts, then fail to drive to conditions as they sought to maintain an average speed.