Toronto police have begun a pilot project testing the use of roadside screening devices for drug-impaired driving.

The project - which continues through to next spring - will test how well officers are able to use certain roadside drug−testing devices on motorists under different weather conditions and at night.

It is part of a national effort aimed at testing how police forces can detect drug-impaired drivers, with forces in Vancouver, Halifax and Gatineau, Que., as well as the Ontario Provincial Police and certain RCMP detachments taking part.

Toronto police say the information they will be collecting will help develop practices for the use of "oral-fluid" screening devices in Canada.

The force also notes that there need to be legislative changes to allow roadside drug screening to become part of the drug-impaired-driving regime before Toronto police can use the devices in actual enforcement situations.

Police say participation in the project is anonymous and voluntary.

They say if a driver shows no sign of impairment, they are eligible to volunteer, and if they do end up testing positive for the presence of drugs, no charges would be laid.

Public Safety Minister Ralph Goodale has said his department and the Canadian Council of Motor Transport Administrators will collaborate with police forces on the project.

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

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.”