1. Road Safety and the Lifeworld: Unintended Social Barriers of Canada’s New Drug-impaired Driving Legislation.
Devon Valentine
Research Associate, Traffic Injury Research Foundation (TIRF)
Ph.D. student, Queen’s University: Department of Sociology

2. Overview
Background
Canada’s THC Per Se Regime
Habermasian Analysis

3. Background
October 2018 recreational cannabis use became legal in Canada.
Previously Canada operated under a behavioural impairment regime for drug-impaired driving.
Post-legalization cannabis-caused impairment is now regulated under a per se regime.

4. Canada’s THC Per Se Regime
The measurement for impairment is based on how many nanograms (ng) of THC per millilitre (ml) of blood (ng of THC/ml).
The currently the limit begins at 2 ng of THC/ml.

5. Canada’s THC Per Se Regime
The law implements these limits through Governor-in- Council regulations.
The Governor-in-Council delegates their authority to the DOJ
The DOJ wrote these limits into administrative regulations, which now have the force of criminal law.

6. Canada’s THC Per Se Regime
Per se limits for drugs have long been sought by the legal and law enforcement communities (Lacey, Brainard, & Snitow, 2010).
It makes their jobs easier.
Previously, successful prosecution of drug-impaired driving was more difficult to achieve.

7. Canada’s THC Per Se Regime
Report on Drug Per Se Limits - Canadian Society of Forensic Sciences Drugs and Driving Committee.

8. Canada’s THC Per Se Regime
“The interest in utilizing a per se approach is an attempt to simplify the adjudication process, facilitate enforcement, and enhance deterrence.”
“The relative simplicity of per se laws, their widespread acceptance, and the demonstrated effectiveness of alcohol per se laws, have bolstered the call that similar limits be established for other drugs in Canada.”

9. Canada’s THC Per Se Regime
BAC limits are based on a well-established dose-response relationship.
THC does not have a comparable consensus about the “benchmark” for impairment.
The substances behave differently in the body.

10. Canada’s THC Per Se Regime
For example, one study found that THC could still be detected at 3 ng/ml 7-days after consumption (Karschner et al., 2009).

11. Canada’s THC Per Se Regime
In a separate study these results were repeated; it was also demonstrated THC was detectable at the 4-week point (Bergamaschi et al., 2013).

12. Canada’s THC Per Se Regime
Lack of consensus about the impairing effect in these instances.

13. Canada’s THC Per Se Regime
One study found limited memory deficits at the 7-day mark. There was no impairment at the 28-day mark (Pope, Gruber, Hudson, Huestis, & Yurgelun-Todd, 2001).

14. Canada’s THC Per Se Regime
Another found that at the 4-week mark there was oral impairment, but not motor impairment (Eldreth, Matochik, Cadet, & Bolla, 2004).

15. Canada’s THC Per Se Regime
Ramaekers, J.G, J.H. van Wel, D.B. Spronk, S.W. Toennes, K.P.C. Kuypers, E.L. Theunissen, and R.J. Verkes Cannabis and Tolerance: Acute Drug Impairment as a Function of Cannabis Use History. Nature: Scientific Reports 6:26843, 1-8.

16. Canada’s THC Per Se Regime
Article speculates that differences in performance for placebo group was due to residual THC levels.
However, this link is not proven.
The primary purpose of this study was to determine the level of tolerance frequent cannabis users had to the impairing effects of THC.

17. Canada’s THC Per Se Regime
“The presence of low levels of THC in frequent users may have caused some degree of subjective high and performance impairment during placebo treatments.”

18. Canada’s THC Per Se Regime
“Psychomotor performance during placebo did not correlate with baseline THC and cannabis use history which is in line with previous studies showing that associations between THC concentrations and performance impairment are generally weak or absent.”

19. Canada’s THC Per Se Regime
“Yet, baseline THC levels were high enough to expect intoxication and mild psychomotor impairment in some individuals.”

20. Canada’s THC Per Se Regime
“It implies that neurocognitive function of daily or near daily cannabis users can be substantially impaired from repeated cannabis use, during and beyond the initial phase of intoxication.”

21. Issue
Hard to differentiate regular users and recent users based on these limits.
Someone who consumed cannabis legally may be prosecuted for impaired driving despite the lack of an impairing effect.

22. Habermasian Analysis Lifeworld and internal colonization.
Welfare state reduced agency among welfare recipients by treating them as clients.

23. Habermasian Analysis
Clients were served on the basis of state systems rather than lifeworld institutions. Equity gapped was widened (Habermas, 1984).
Ex. Food Stamps (Sarat, 1990), Speed Signs.

24. Habermasian Analysis
Colonization process for drug-impaired driving is marked by an attempt to make the job of criminal justice practitioners less burdensome.
This causes lifeworld protections, such as those for private autonomy, to diminish in the courtroom.

25. Habermasian Analysis
Regular recreational cannabis users should abstain from driving to avoid the risk of criminalization.
The legislative initiative that was meant to empower cannabis-user agency instead prevents them from legally driving.

26. Habermasian Analysis
By attempting to alleviate the criminal status of cannabis users, the state instead potentially further criminalizes them.

27. Conclusion
Society has a vested interest in preventing and reducing impaired driving for the betterment of all road users.
There is an undeniable tension between the need to empower cannabis user-agency while at the same time up holding public safety.

28. Conclusion
The intent to uphold public safety is admirable, but the gap in the scientific evidence for these limits is concerning.
The focus on creating a deterrent effect may have unintended consequences.

29. The End

30. References
Bergamaschi, M. M., Karschner, E. L., Goodwin, R. S., Scheidweiler, K. B., Hirvonen, J., Queiroz, R. H., & Huestis, M. A. (2013). Impact of prolonged cannabinoid excretion in chronic daily cannabis smokers' blood on per se drugged driving laws. Clinical chemistry, 59(3),
Bolla, K. I., Brown, K., Eldreth, D., Tate, K., & Cadet, J. L. (2002). Dose-related neurocognitive effects of marijuana use. Neurology, 59(9),
Eldreth, D. A., Matochik, J. A., Cadet, J. L., & Bolla, K. I. (2004). Abnormal brain activity in prefrontal brain regions in abstinent marijuana users. Neuroimage, 23(3),
Habermas, J. (1984). The theory of communicative action (Vol. 2). New York: Beacon press.
Karschner, E. L., Schwilke, E. W., Lowe, R. H., Darwin, W. D., Pope, H. G., Herning, R., ... & Huestis, M. A. (2009). Do Δ9‐tetrahydrocannabinol concentrations indicate recent use in chronic cannabis users? Addiction, 104(12),

31. References
Lacey, J., Brainard, K., & Snitow, S. (2010). “Drug per se laws: A review of their use in States” NHTSA. No. HS Retrieved at on 11/12/18.
Peaire, A.; Filbert, A.; Smith, D.; Beirness, D.; Viel, E.; Wallage, R. (2017) Report on Drug Per Se Limits. Canadian Society of Forensic Sciences Drugs and Driving Committee. Ottawa, Canada.
Pope, H. G., Gruber, A. J., Hudson, J. I., Huestis, M. A., & Yurgelun-Todd, D. (2001). Neuropsychological performance in long-term cannabis users. Archives of general psychiatry, 58(10),
Ramaekers, J.G, J.H. van Wel, D.B. Spronk, S.W. Toennes, K.P.C. Kuypers, E.L. Theunissen, and R.J. Verkes Cannabis and Tolerance: Acute Drug Impairment as a Function of Cannabis Use History. Nature: Scientific Reports 6:26843, 1-8.
Sarat, A. (1990) ‘The Law is All Over’: Power, Resistance and the Legal Consciousness of the Welfare Poor. Yale Journal of Law and Humanities Vol. 2. pp