Comment You left out the most important part! (Score 1) 1
No Effect from Legalization: The rate of drivers who tested positive for THC did not change significantly before or after legalization (42.1% vs. 45.2%), indicating that legal status did not influence the behavior of those who chose to drive after use.
This kind of research is nearly always improperly presented. An accurate title would be "In Ohio, Marijuana Legalization Has Not Prevented Intoxicated Driving In the Last Six Years".
It's also important to note that societal behaviors change across generations, so it's no surprise there was no sudden drop. We will have the first real results in another 20 years or so. Another thing that matters is how the region of interest differs from other regions.