Author: David S.R. Parker

Proposed legislation to legalize (and regulate) marijuana use and sale (Cannabis Act) is currently before the Federal Parliament.  Even though cannabis remains illegal at this point, drug-impaired driving is already a significant problem, especially among young drivers. Studies reveal that between 2000 and 2010, 16.6% of fatally injured drivers tested positive for cannabis use, and 40% of those were between the ages of 16-24.  When legalised, it is suspected this will become an even larger problem.

Operating a motor vehicle while impaired by cannabis which results in a motor vehicle accident can amount to both negligence in a civil action and a criminal offence.

Like alcohol, cannabis use can impact a driver’s ability to safely operate a vehicle.  Demonstrated deficits such as: in tracking, reaction time, visual function, concentration, short-term memory, and divided attention have been identified. Cannabis has been found to specifically impair performance on divided attention tasks — the ability to monitor and respond to more than one source of information at a time and respond to unexpected events.  The combination of cannabis with even small amounts of alcohol can significantly increase the negative effects on driving skills.

It is already a criminal offence to operate a motorized vehicle (or boat, plane, ATV, snowmobile, etc.) while under the influence. The proposed “Criminal Code Amendment Act” will make a criminal offence for an individual to have a blood drug concentration exceeding the prescribed limit while driving or within 3 hours of driving.  The proposed “prescribed limits” include:

Drivers who are impaired by drugs are currently subject to the same penalties as those impaired by alcohol. On a first offence, impaired drivers face a minimum fine of $1,000, a mandatory driving prohibition of 12 months and a possible jail sentence of up to 18 months. On a second offence, a mandatory 30-day minimum jail sentence and a two-year prohibition from driving are imposed. Third and subsequent offences result in imprisonment for a minimum of 120 days plus a three-year driving prohibition. Impaired drivers who cause an accident resulting in bodily harm face a maximum 10-year period of incarceration, and a life sentence in the case of causing death.

Because the detection of cannabis use among drivers is more difficult and complex than for alcohol, the proposed amendments introduce the use by police of “oral fluid drug screening” devices (somewhat similar to roadside alcohol screening devices). Following a legal roadside stop, police officers will be authorized to demand that a driver provide an oral fluid sample if they reasonably suspect that a driver has drugs in their body.

Individuals using marijuana will normally display one or more telltale signs of use including:

These signs are usually sufficient for police officers to form a reasonable suspicion of drug use, which allows them to proceed with a demand for the driver to perform the Standardized Field Sobriety Test (SFST)—involving horizontal gaze nystagmus (testing of tracking and involuntary movement of the eyeball), one leg stand, walk and turn testing and/or make a demand for an “oral fluid drug screening” sample to provide oral or urine samples for testing.  Those test results can form the basis for an impaired driving charge.

In order for a blood sample to be obtained, a positive reading on the “oral fluid drug screening” device combined with findings from the SFST test provides grounds to permit a drug evaluation by an “Evaluating Officer.”  Drug “Evaluating Officers” are specially trained in the Drug Evaluation and Classification (DEC) program. This procedure involves a series of tests of coordination and divided attention, eye examinations, blood pressure and temperature measurements, observations of the suspect, and an interview.

The DEC program is designed to allow the officer to determine whether the suspect is impaired, whether the impairment is due to drugs, and which category or categories of drugs are most likely to be responsible. Cannabis has a unique DEC profile that includes poor coordination and balance, reduced ability to divide attention, elevated pulse and blood pressure, dilated pupils, inability to cross one’s eyes, reddening of the conjunctiva, and eyelid or body tremors.  The DEC evaluation targets these profile factors.

This evaluation will result in a demand for a blood sample if sufficient evidence of impaired driving is identified.  The combination of blood test results and the DEC evaluation findings will result in drug-impaired driving charges to be laid.

The new “oral fluid drug screening” devices will provide another tool for police to identify drug-impaired drivers.  We will probably see a number of cases challenging the accuracy of the devices and whether the police officer had reasonable grounds to make a demand.

In motor vehicle accident negligence cases, it will still require an expert toxicology witness to provide an opinion as to whether the level of THC in the defendant driver’s system was sufficient to impair him or her and proof of the actual impact of THC on driving abilities and skills.