In this post last year, titled “New report suggests big increase in pedestrian fatalities in marijuana legalization states… but only by leaving out California,” I noted a big report by the Governors Highway Safety Association (GHSA) which expressed concern about pedestrian fatalities in 2017 and spotlighted that the legalization of recreational marijuana in several states seemed to correlate with an uptick in pedestrian fatalities in those states. That prior GHSA report stressed in graphic and text how “seven states (Alaska, Colorado, Maine, Massachusetts, Nevada, Oregon, Washington) and DC that legalized recreational use of marijuana between 2012 and 2016 reported a collective 16.4 percent increase in pedestrian fatalities for the first six months of 2017 versus the first six months of 2016, whereas all other states reported a collective 5.8 percent decrease in pedestrian fatalities.”
But, as I lamented in my post, the GHSA accounting completely left out the state of California (which also legalized recreational use of marijuana in 2016), perhaps because the GHSA data from that year showed a big decrease in pedestrian fatalities in that state for the first six months of 2017. Had California been included in the analysis by GHSA, as it rightly should have been in that prior report, the data in last year’s report on legalized recreational use of marijuana and pedestrian fatalities would have looked a whole lot different.
Fast forward a year, and now the GHSA has recently released its latest data and report on pedestrian fatalities. This new GHSA report expresses again a deep concern with increases in the number of pedestrian fatalities. But while last year’s report mentioned marijuana 14 times, this year’s report does not use the word once and does not spotlight or even mention the states that legalized recreational use of marijuana between 2012 and 2016. Why not? Perhaps because the story looks very different this year, as seven of the eight states to legalize recreational use of marijuana between 2012 and 2016 had notable decreases in pedestrian fatalities according to the latest GHSA data: Alaska down 29%, California down 8%; Colorado down 8%, Maine down 40%, Massachusetts up 9%, Nevada down 28%, Oregon down 18%, Washington down 4%. These numbers would be notable even if pedestrian death were flat in other states, they are particularly encouraging given that so many other states saw increases in pedestrian fatalities in the first part of 2018.
Critically, these latest GHSA data showing a decrease in pedestrian fatalities in so many which have legalized recreational use of marijuana do not prove any causal relationship. And, in the same spirit, the older data did not clearly prove anything, either. Rather, there is every reason to suspect this is all just usual statistical noise.
Prior related post:
New report suggests big increase in pedestrian fatalities in marijuana legalization states… but only by leaving out California