More than 700 drug drivers are being caught on Victoria's roads each month as police go all-out to catch those trying to avoid detection.

New analysis shows methylamphetamine - also known as speed or ice - was present in three quarters of all detections, while almost one in five drivers caught had multiple illicit drugs in their system.

Superintendent Justin Goldsmith, Road Policing Command, said drug drivers who think they can outsmart police should think again.

"We're out anywhere, any time testing for drugs," he said.

"Every highway patrol car is a drug bus which means there's nowhere to hide.

"The penalties for drug driving are severe, even if you're a first-time offender.

"We can also link drug users with support services to help break the cycle of harm."

Victoria Police conducts 150,000 roadside drug tests a year with units out anywhere, any time.

Last financial year there were 8426 drug driving detections.

Just over 75 per cent of detections were for methylamphetamine.

The penalties for getting behind the wheel on drugs are severe.

Even if you’re a first-time offender you’ll be fined $593 and have your licence or learner permit suspended for six months.

Police also have the power to impound your vehicle for drug driving offences.

For more information about Victoria Police's drug driving enforcement go to https://www.police.vic.gov.au/road-policing.