Cambridgeshire Police are using US-style sobriety tests to target drug-impaired drivers in Peterborough.
Officers have been trained in field impairment testing (FIT) techniques to identify those driving under the influence of drugs.
Insp Chris Skepper said that drivers may be required to undertake tasks that require co-ordination, including walking in a straight line.
He added that those caught could face a £5,000 fine and six months in prison.
The police are working with SaferPeterborough, a partnership of organisations that works together to reduce crime and anti-social behaviour within the city, to raise awareness of the dangers of driving under the influence of drugs.
Posters and leaflets have been distributed throughout Peterborough warning drivers that "your eyes will give you away".
Clair George, road safety officer for the partnership, said: "Drug-driving is as dangerous as drink-driving and the same legal implications apply.
"This campaign is to make people aware of both the legal and the personal consequences of drug-driving."
Insp Skepper described driving under the influence of drugs as "a growing problem" and added that some prescription drugs could also impair a driver's ability to control his vehicle.
"I have been present at one fatal road traffic collision where two people were killed because the driver was allegedly on drugs at such a level that it affected their driving," he said.
"That's what can happen and people must bear in mind that they could kill somebody."