OTTAWA -- Drivers in some jurisdictions may soon find themselves asked by police to volunteer for a saliva test, part of a pilot project aimed at detecting drug-impaired drivers.

The federal government, the RCMP and a number of police departments across the country will conduct the experiment to see how well certain roadside testing devices work to detect drugs.

Public Safety Minister Ralph Goodale says his department and the Canadian Council of Motor Transport Administrators will collaborate with police forces on the project, which will look at how two different devices work under varying weather conditions.

The "oral fluid" screening systems test saliva for the presence of drugs, including cannabis, cocaine, methamphetamine and opioids.

The announcement comes a day after a federal task force delivered a series of recommendations about legalizing cannabis and raised questions about detecting drivers impaired by marijuana.

Police forces in Toronto, Vancouver, Halifax and Gatineau, Que., will take part in the project, along with the Ontario Provincial Police and RCMP detachments in North Battleford, Sask., and Yellowknife.

Police officers will be trained in the use of two types of screening devices and will use them in operational settings, but only with drivers and passengers who volunteer to anonymously provide a sample.

The results will not be used in any court or administrative proceeding, the department said.

"The testing results will help establish possible future operating procedures," the department said in its announcement. "In parallel, Canadian standards for oral fluid devices will still need to be established before a government procurement process for the device can be launched."

The cannabis task force recommended more study to determine the links between traffic crashes and levels of THC, the active ingredient in marijuana, and a national education strategy about the effects of cannabis consumption.

Goodale said the pilot project will help determine how police services can counter drug-impaired driving.

"Testing these new drug screening devices is an important step in our ongoing effort to enhance the enforcement of drug-impaired driving laws, reduce drug-impaired driving and improve the safety and security of all Canadians," he said.

Currently, the Criminal Code authorizes police officers to conduct a standard field sobriety test on a suspected impaired driver. If the officer has a reasonable belief that an offence has been committed, a specially trained officer can be called to conduct a drug recognition evaluation.

Some police forces have expressed concern that legalizing marijuana will produce problems on the roads. The Canadian Association of Chiefs of Police welcomed the pilot project.

"Keeping impaired drivers off the road is a priority for the CACP, " said association president Mario Harel. "The CACP welcomes the pilot testing of these devices as they are another potential tool for Canadian police to help keep roads safe."