WIMMERA drug-driving cases have increased by 50 per cent in the past year.
Horsham Highway Patrol Sergeant Wayne Caddy said officers detected five to six 'moronic' drivers with illicit drugs in their system every week.
Police detected six over the Australia Day long weekend alone. The drivers initially tested positive to cannabis or amphetamines.
Sgt Caddy said he was also alarmed by the fact that many drug-drivers were Wimmera people.
"We believe the numbers are well up; by about 50 per cent," he said.
"Year on year, the percentage continues to rise.
"It is amazing that these people are prepared to take this risk and put themselves, their passengers and other road users at risk.
"It is sheer stupidity. We will target people who we know are associated with illicit drugs. Drivers can expect to be drug-tested at any time. If people are prepared to lose their licence, police will take it off them."
Sgt Caddy said some drivers had been caught multiple times, including a Horsham driver who tested positive four times in six months.
He said illegal drugs impaired a person's driving ability as much as alcohol.
The Horsham police service area covers Horsham, West Wimmera and Hindmarsh municipalities.
Ararat Acting Sergeant Shaun Allen of Northern Grampians Highway Patrol said drug-testing had revolutionised road policing.
"More drivers are testing positive to illegal drugs because we are doing more tests," he said.
"Now we have the ability to drug test, we have a pretty good strike rate. People are surprised that police can drug test them."
Acting Sgt Allen estimated Northern Grampians members caught fewer than one drug-affected driver each week.
The Northern Grampians police service area covers Northern Grampians, Ararat and Yarriambiack municipalities.
Sgt Caddy said while the Australia Day long weekend was free from serious or fatal road accidents, he was concerned by the number of drivers caught speeding and-or drink or drug-driving.
Police detected three speeding drink-drivers on the Western Highway at the weekend.
Their blood-alcohol readings were 0.111, 0.074 and 0.163. The top speeds recorded were 167 and 140 kilometres an hour.
Sgt Caddy said one of the drivers was unlicensed and told police he had become lost travelling from Kyneton to Mildura. Police caught the man at Kaniva.
Sgt Caddy said another driver's excuse was that he was running late to pick someone up from Melbourne Airport.
"It's absolutely ridiculous," he said.
"People who drink and drive think they might be over, but they are prepared to take the risk.
"These drivers were sorry for being caught, but did not care about other road users they might potentially harm.
"A driver who is more than double or triple the legal blood-alcohol limit does not have proper control of their car."
Wimmera police also detected four unlicensed drivers and fined a further 40 for speeding.
Sgt Caddy said police will also charge a South Australian driver on summons with possession of goods suspected of being the proceeds of crime.
Officers stopped the man near Kaniva and allegedly found $27,000 cash hidden in his car at the weekend.