Highway Patrol Senior Sergeant Stuart Gale said drug driving was an increasing problem on roads across the region.

"It is one of our top three issues, along with speed and distraction, and features continually in our serious injury and fatality road trauma," he said.

"We've seen increases in drug impairment and driving since the inception of drug testing but it's a big concern of mine that we are seeing this trend where drug impairment is overtaking alcohol impairment in our statistics."

It comes as Victoria Police strengthens its road policing response with a new trial commencing this week.

While drivers will still be required to undertake the Preliminary Oral Fluid Test (POFT) and the Oral Fluid Test (OFT), if a test returns a positive result for drugs, an infringement will be immediately issued and a driving ban imposed.

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Drivers who commit their first offence will be issued with a $495 infringement notice on the roadside.

Meanwhile, a permanent increase to the imposed driving ban for drivers caught with drugs in their system has also been introduced -- it is now a minimum of 12 hours and up to 24 hours.

Assistant Commissioner Libby Murphy said the trial would expedite the process of removing drug drivers from Victorian roads.

"Until now, police would have to wait for a toxicology certificate before issuing a drug driver with an infringement notice and the subsequent imposition of a six-month licence suspension", AC Murphy said.

"This delayed process creates a risk that the offending driver will continue to drive while still having drugs in their system which is seriously concerning.

"You should not and do not have the privilege to drive a vehicle if you have drugs in your system, so we're taking steps to remove that privilege a lot faster if you're caught doing the wrong thing."

Drivers still have the option to to challenge an infringement in court.

Senior Sergeant Gale said impaired driving was "very dangerous".

He said police would continue to enforce and take appropriate action against impairment on the roads and would increase testing as technology and availability allowed.

The technology and processes are continuing to evolve and AC Murphy said it was "extremely accurate".

"The chance of someone receiving a false reading is very small. But rest assured, if an error is detected during laboratory testing, the infringement will be withdrawn.

"What we hope to see from this is a smoother, more efficient system that helps to remove drug drivers from the roads making them safer for everyone else."