This seems like an intentionally misleading title, since they don't mention that the study was for one county (Montgomery County) in Ohio, which is basically just Dayton, OH and surrounding rural area - I'm sure you can pick other counties in the US which have either very high representation of THC users or very low representations. Without knowing how other counties score in terms of driver fatalities and THC, this…
Per more Pew Research data, also from 2023, Ohio seems to have an average, if not a less than average, concentration of cannabis dispensaries, compared to other states where CBD products were legal. Montgomery County, OH is located in the bottom-left quarter of Ohio, and sits in a region with lower dispensary density than many comparable U.S. districts. [2]
Given that usage metrics mirror the national mean despite a lower-than-average retail presence, I think this dataset is a pretty fair "middle america" benchmark.
[1] https://www.statista.com/statistics/723822/cannabis-use-with... [2] https://www.pewresearch.org/short-reads/2024/02/29/most-amer...