One in 37 Victorian truck drivers tested positive to drug-driving, almost double the national figure, in a police blitz this week.

A National Day of Drug Testing, held on Monday as part of Operation Austrans, focused on truck and other heavy-vehicle drivers across the state, and targeted drugs, alcohol, fatigue, and traffic and compliance offences.

One in 37 truck drivers tested in a recent Victoria Police blitz were caught driving while on drugs. Credit:Rob Homer

Acting superintendent of road policing operations Stuart McGregor said the results from Monday painted an alarming picture of drug culture within the trucking industry.

"None of us want to think that the 12-tonne truck approaching us at 100km/h on the freeway is under control of a person impaired by illicit drugs," Superintendent McGregor said.