Point-to-point speed cameras will start operating on the Victor Harbor Road, south of Adelaide, next week.

They measure drivers' average speed between two points as well as how fast they are travelling at the actual camera locations, and will be on a 5 kilometre section of road between McLaren Vale and Willunga.

South Australian Road Safety Minister Tony Piccolo said point-to-point cameras earlier started operating on the Dukes Highway and Port Wakefield Road and had proved their worth in getting drivers to adhere to speed limits.

"When you have point-to-point cameras you have 'police on the beat' there 24-7," he said.

"It just helps with [speed] compliance but also helps to reinforce the message that speeding kills."

Mr Piccolo said the Victor Harbor Road cameras had been tested rigorously and would be activated from next Monday.

"This section of road was chosen based on its high crash rate and consistent speed limit between the camera sites," he said.

"Approximately 11,000 motorists use Victor Harbor Road each day, with 318 crashes recorded between 2010 and 2014 resulting in four deaths and 47 serious injuries."

More point-to-point monitoring will be in place soon on the South Eastern Freeway, Northern Expressway and the Sturt Highway.