The highest speed detected was a driver travelling 140 kilometres an hour in an 80 km/h zone.

Another driver was caught doing 81 km/h in a 60 km/h zone while the front passenger carried an eight-week-old baby in their lap.

There were also 30 drivers who returned a positive roadside drug test over the four-day period.

"One hundred and forty five random drug tests were conducted during the four-day operation and to detect 30 positive samples is alarming," Acting Station Sergeant Marcus Boorman said.

"That is approximately one positive test for every five tests conducted.

"Furthermore, during an apprehension of a male driver for drug driving offences it was discovered the driver was arrested a week earlier for similar offences, and this was the sixth time he's been apprehended for drug driving and traffic offences," he continued.

"That's unacceptable and concerning behaviour that could have fatal consequences."