Tiesitkö, että USAn Tieturvallisuuslaitoksen vuonna 2015 tekemän tutkimuksen mukaan marijuanan ei ole todettu haittaavan autolla ajoa

kun otetaan huomioon mm. ajajan ikä ja sukupuoli. Joissakin toisissa tutkimuksissa haitallinen vaikutus on taas havaittu.

This study of crash risk found a statistically significant increase in unadjusted crash risk for drivers who tested positive for use of illegal drugs (1.21 times), and THC specifically (1.25 times). However, analyses incorporating adjustments for age, gender, ethnicity, and alcohol concentration level did not show a significant increase in levels of crash risk associated with the presence of drugs. This finding indicates that these other variables (age, gender ethnicity and alcohol use) were highly correlated with drug use and account for much of the increased risk associated with the use of illegal drugs and with THC. This study found a statistically significant association between driver alcohol level and crash risk both before and after adjustment for demographic factors.

https://trid.trb.org/view.aspx?id=1343066