Hamilton police manned a road block this week and conducted just 12 drug tests (they are expensive), catching four drivers under the influence of drugs.

That's a 33 per cent strike rate - which is an alarming statistic given the effects of drugs on drivers.

Alcohol and Drug Foundation spokeswoman Laura Bajurny said there was no safe level of drug use.

"It's dangerous to drive after the use of any drug," Ms Bajurny said.

"It is especially risky to drive if a person mixes drugs, including alcohol because it can amplify the effects of both drugs."

Ms Bajurny said drugs affected everyone differently.

"Drugs stay in the system for longer than a person may feel their effects," she said.

"A person can still test positive on a roadside drug test even if they no longer feel the effects of a drug."

Drivers under the influence of amphetamines may experience increased confidence, a sense of invincibility and poor muscle control.

"People with over-confidence may take more risks when driving, which increases the chance of an accident," Ms Bajurny said.

In addition to that, the symptoms of withdrawing from drugs can affect a person's ability to drive safely.

"If a person has been awake overnight or for several days, the lack of sleep negatively impacts their ability to drive as well," Ms Bajurny said.

Cannabis can also impact a person's driving by slowing their reflexes, impairing short-term memory and altering perceptions.

"This means a person may not be able to react quickly when needed and may be absent minded or distracted when they need to be focused and attentive," Ms Bajurny said.

"People who are new or infrequent cannabis users are specifically at risk."

Ms Bajurny said prescription medications like benzodiazepines (tranquilizers) and opioid painkillers can also affect a person's ability to drive safely.

"The effects of benzodiazepines, such as feeling drowsy and reduced concentration and coordination, can affect driving ability," she said.

"The effects of opioid painkillers can also include drowsiness and confusion."

Ms Bajurny said people with reduced concentration and coordination were unable to respond as quickly when driving, which increased the chance of an accident.

Former Mortlake man Paul Levey, who turned to drugs as a way to cope after he was the victim of sexual abuse, has witnessed the devastating affects of drug driving.

"When I was about 16 my mate and I had been smoking pot and we were going to see friends," Mr Levey said.

"He lost control on a corner and we flipped into a lagoon of the Murray River in Albury."

Mr Levey's friend didn't survive the crash.

He said he believed the cannabis contributed to the crash, saying it made you feel "bullet proof".

Mr Levey said he was relieved police could now test drivers for drugs because he knew how dangerous it was to get behind the wheel while under the influence.

Warrnambool police divisional Inspector Paul Marshall said when he was working in Melbourne and associated with music festivals one of the aspects he found surprising was the level of acceptance of illicit drug use.

"It was accepted as the norm and I think that has permeated through our community and society," he said.

"Illicit drug use in the community impacts in so many ways, personal relationships, health issues, violence and crime.

"We've all heard of people on four-to-five day ice benders, rampaging offending, home burglaries and thefts. That all has a huge impact."

Inspector Marshall said he remembered the heroin use of the 1990s when people took drugs and generally went to sleep.

"Ice use is problematic. The resulting community harm can be extreme, the threats, violence, the level of aggression towards partners, family members, emergency service workers, hospital staff.

"The negative impacts are far reaching," he said.

"Our drug focus is around mid to higher level traffickers.

"We want to squeeze that supply chain the best we can."

The inspector said community information was the key to fighting drugs.

"There are constant changes in term of social media that we have to contend with and we're working through those issues," he said.

"But, if members of the public are seeing numerous people attending an address for a short time and then leaving we want to know about it.

"That intelligence about honeypots is key to determining pick-up points."

Inspector Marshall said education was a key component in fighting against drug use - especially in schools.

"The grim reaper ads worked to raise the awareness of the dangers of smoking," he said.

"Perhaps we need something equally as graphic to warn about the use of illicit drugs.

"There's no such thing as acceptable illicit drug use. They are all pathway drugs to something more serious which has and does have massive impacts on lives.

"We see it every day in our work."

The recent anecdotal trend shows long term drug users developing acquired brain injuries.

Inspector Marshall said the harm of drug use then potentially became permanent.

"We are getting better at intervention, about providing programs to give people the choice to not take illicit drugs," he said.

"Unfortunately a lot of the problems around homelessness, particularly in Melbourne, is about people making the choice to continue using drugs.

"The easiest way to help people get off drugs is to never get hooked. To not take them.

"But, education and awareness are the keys to turning around the percentage of the public who think illicit drugs are acceptable."

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