The assistant commissioner on Tuesday announced he will hang up his uniform on August 4 to take up the executive role of government and defence president for logistics company Linfox.

"I joined the job in 1985 as a teenager and have spent well over half my life in policing, and it's been amazing seeing the best and worst in our community," Mr Fryer said in a statement.

"I've enjoyed it all, but of all the policing roles I've had, the most rewarding has been that of leading road policing.

"If we get it right, and get the message of road safety into the hearts and minds of all Victorians, we save lives."

Mr Fryer led the effort to drive down the road toll since September 2015 and previously worked across organised crime, counter-terrorism and intelligence and covert policing.

Police Minister Lisa Neville credited Mr Fryer with getting dangerous people off the road through the rollout of number plate recognition technology and expanding the drug testing regime.

"He has been responsible (for) ... getting the message out that road safety is an absolutely critical part of policing. And we've seen the outcomes in terms of the road toll," she said.

"Victoria Police is stronger and our road safety message is stronger because of the work that Doug Fryer has done."

Assistant Commissioner Stephen Leane said the next person in the role had big shoes to fill.

"We need somebody who can be consistent, be aware of what's going on in the road trauma space. But also connect - not just with community, but government and across Victoria Police," he said.

Mr Fryer will join Linfox on August 24, based in Melbourne, replacing Major General Mick Slater.

Australian Associated Press