https://www.sydney.edu.au/news-opinion/news/2021/12/02/thc-blood-saliva-poor-measures-cannabis-impairment-lambert-study.html
https://www.sciencedirect.com/science/article/pii/S0149763421004978?via%3Dihub#bib0145
Hopefully studies like this can help us get a better understanding of impairment and a persons ability to operate a motor vehicle while having thc in their system. I think it's one the limiting factors for a lot of people to try medical cannabis for fear of losing their licence and essentially their mobility.