The widow of a police officer killed while working alone has pleaded against a proposed plan to allow highway officers to operate solo. 

Victoria Police is mulling a trial of "one-up" highway patrols, allowing officers to work on their own so long as they are in close proximity to another member. 

Assistant Commissioner Mick Hermans said the change would support a stronger police presence on roads across the state.

"A highly visible police presence provides a significant general deterrence and will lead to less road trauma," he said in a statement shared with AAP. 

He insisted the changes would be opt-in and subject to occupational health and safety assessments, and officer safety remained the force's top priority. 

But the announcement immediately sparked backlash from the widow of a police officer who was murdered in the line of duty.

The current policy was introduced in 2015, years after a coroner recommended scrapping one-up patrols following the murder of Senior Constable Anthony Clarke. 

The father of one, 37, was shot dead in 2005 while conducting a roadside breath test at Launching Place, a town in the Yarra Valley.

A 2010 coronial inquest found working alone, which was Senior Constable Clarke's preference, contributed to his death.

Coroner Kim Parkinson recommended the practice be banned in certain high-risk situations, including late-night and remote area intercepts. 

The slain officer's widow Tina Hogarth-Clarke said it was "frankly offensive" police were now considering reversing the policy.

"There is no doubt in my mind that my husband SC Tony Clarke would be alive today if he was working two-up the night he was murdered," she said. 

"It is unsafe and frankly offensive that my husband's death and the learnings from it are so easily forgotten."

Mr Hermans said the changes were not a reflection of vacancy levels within the force. 

"The proposed change is not because of vacancy numbers - the same number of police would be deployed," he said.

But the state's police union has pushed back on that statement, arguing resourcing constraints were putting officer safety at risk. 

"I get it, there's a shortage of cops in Victoria," chief executive at the Police Association of Victoria Wayne Gatt told reporters on Wednesday. 

"Deal with the issue, don't gamble on the safety of your people."

He said he had been lobbying against the changes for months and rejected claims new technologies including tasers would help in one-up situations. 

"When the inevitable happens and one of my members is seriously injured, or worse dies at work, the people that make this decision will need to look at themselves in the mirror," he said.

Any changes will be subject to engagement with the police workforce and would begin with a pilot to allow for refinement.