Hamilton police Highway Patrol Sergeant Scott Williams said officers has detected the lowest number of offences during Operation Amity in the Southern Grampians and Glenelg regions for the past five years.

He said just under 100 offences were detected with five people picked up for  alcohol or drug-affected driving.

Officers conducted 2500 preliminary breath tests and caught three drunk drivers.

"What stood out was that the bulk of the offences were speeding offences and that's been the recent trend over long weekends," he said.

"We were rapt there were no serious injury or fatal collisions in this area. There were a lot of tourists around, especially in Portland, and we were very pleased the majority were doing the right thing," he said.

Warrnambool police area investigation, response, tasking and coordination Inspector Paul Ross said it was pleasing there had been no road fatalities this year in the district.

"We've had a few serious collisions during the month, that's disappointing and we're working through those," he said.

"After the weekend we're generally happy with driver behaviour and very pleased to be fatality free so far this year."

Inspector Ross said the next statewide campaign would be Operation Arid during the long weekend in March which coincided with the Port Fairy Folk Festival.

"This week we've got Operation Cross Borders running which looks at activity between Victoria and South Australia targeting speed, alcohol and drug-related driving offending," he said.

"That's run in coordination with South Australian police and is a good way of maintain those networks. Drug driving continues to be an issue of concern," he said.