Operation Troika took place on Tuesday and Wednesday in Tumut and surrounding areas.

Officers undertook 600 stationary mobile breath tests and 60 mobile breath tests as part of the operation.

Of the 173 random roadside drug tests, four positive results were obtained, including two heavy vehicle drivers and three driving prohibition notices.

Thirty-nine infringement notices were issued for a range of offences relating to speeding, work diaries, defective vehicles, dimension breaches and inadequate load restraint.

A further 11 defects were issued against heavy vehicles.

Riverina Police District Commander, Superintendent Bob Noble said recent incidents sparked the police operation.

"Police held concerns following several recent heavy vehicle crashes and incidents in the Tumut area," he said.

"Driver error, inadequate load restraints and poor mechanical standards were all contributing factors to recent crashes, and this operation really focused on targeting those unsafe behaviours.

"We strongly encourage drivers of heavy vehicles to ensure they are practicing safety at all times. This means checking your load, taking regular breaks and complying with road rules and relevant legislation."

Operation Troika was established by officers attached to Riverina Police District and the Traffic and Highway Patrol Command, supported by the Heavy Vehicle Traffic Taskforce and the Random Drug Testing Unit.