[the-dude]

The title implies cannabis involvement in the crashes, but this is not at all clear, from TFA:

Most cannabis tests do not distinguish between any past use and acute intoxication, and implementing standardized thresholds is challenging due to tolerance from regular use.

[josefresco]

Also...

"“Our testing methods for cannabis remain suboptimal and individuals can test positive for cannabis weeks after they have consumed it,” says study lead author Marlene Lira, an epidemiologist at BMC."

[vollmond]

So as cannabis use becomes more legal, more people who have crashes have used cannabis in the past. What an awful title.