A new report from the Traffic Injury Research Foundation (TIRF) contains a statistic that deserves attention: in 2023, 41.2% of the road deaths in its Canadian database involved at least one driver who tested positive for drugs. Alcohol was involved in 29.3%.
The findings are contained in TIRF’s Drug Use in Fatal Collisions in Canada | 2000-2023 fact sheet. The report examines information from TIRF’s National Fatality Database, which combines police-reported information with data from coroners and medical examiners.
There is an important qualification to the 41.2% figure. It does not mean that drugs impaired a driver in 41.2% of fatal collisions, nor does it mean that drugs caused those collisions.
TIRF classifies a fatality as drug-related when at least one driver involved in the collision tests positive for a drug. The substances can include cannabis, illicit drugs, prescription medications and over-the-counter medications. A positive toxicology result establishes the presence of a substance, but it does not by itself establish impairment or causation.
Even with that qualification, the change over time is striking. TIRF recorded 571 road deaths involving at least one drug-positive driver in 2023, compared with 487 in 2019 and 230 in 2000. The proportion increased from 10.7% in 2000 to 35% in 2019 and 41.2% in 2023.
There is another reason to be cautious about comparing the earliest and latest numbers. Drug testing of fatally injured drivers was much less complete in the early years of the study. TIRF reports a testing rate of about 49% before 2010 compared with 82.5% from 2011 onward. Better testing and detection therefore account for at least some of the apparent increase.
The more recent data are nevertheless revealing. Between 2019 and 2023, 53.7% of tested fatally injured drivers were positive for at least one drug. The percentage was 63.8% among drivers aged 25 to 34. It was 42.1% among drivers aged 16 to 19 and 43.8% among those aged 65 and older.
The timing of these collisions is also interesting. Between 2019 and 2023, 47.7% of drug-positive drivers in fatal collisions were recorded between 3:00 and 5:59 in the morning, while 41.9% occurred between 9:00 p.m. and midnight. Drug-related fatalities were more common on Saturdays than Mondays, and 50.6% of fatalities involving a single occupant were classified as drug-related, compared with 35.6% involving vehicles with two or more occupants.
Cannabis deserves particular attention because recreational cannabis became legal in Canada in October 2018. TIRF found that the average percentage of fatally injured drivers testing positive for cannabis was 22.4% before legalization and 27% afterward. Cannabis-positive results rose from 22% in 2013 to 30.4% in 2020, but declined to 25.2% in both 2022 and 2023. TIRF says more monitoring is needed before conclusions can be drawn about the longer-term effect of legalization.
There is also a useful lesson in comparing these findings with B.C.’s police enforcement statistics. B.C. has recorded an increasing use of its drug-impaired-driving enforcement tools since they were introduced, but those numbers do not tell us whether drug-impaired driving itself is becoming more common. Police are detecting and investigating living drivers they encounter, while TIRF’s fatal-collision data rely heavily on toxicology conducted by coroners and medical examiners after a death.
Those are different measurements. A roadside drug screen is limited to certain substances and is part of an investigation based on a driver’s behaviour and circumstances. A post-collision toxicology test can identify substances that were never detected by police at the roadside. Conversely, neither type of positive test, by itself, proves that a drug impaired the driver or caused the collision.
British Columbia is not included in TIRF’s 2000-2023 figures because B.C. coroner data for 2023 were unavailable when the fact sheet was prepared. That means the 41.2% figure should not be described as a B.C. statistic.
The practical message for drivers is considerably simpler than the statistics. Cannabis, illegal drugs and some prescription and over-the-counter medications can affect the skills required for safe driving. If you have used cannabis, B.C. guidance is straightforward: don’t drive. If a medication or other substance can impair you, don’t drive until you are confident that you are safe to do so.
The TIRF report gives us good reason to pay attention to drugs and driving. It also provides an important reminder about statistics: we need to understand exactly what the numbers measure before deciding what they mean. Canonical URL:https://www.drivesmartbc.ca/impaired-driving/drugs-and-fatal-collisions-what-canadian-numbers-really-tell-us
