Legal marijuana did not lead to increase in deadly “driving while stoned” (apparently)
Contrary to some initial reports alleging increased “driving while stoned,” the federal government’s comprehensive tabulations indicate fatal traffic crashes involving marijuana-impaired drivers decreased in Washington and Colorado following semi-legalization of marijuana in December 2012. The 24 percent and 28 percent respective declines in the proportions of drivers in fatal accidents in the two states who tested positive for marijuana in the first full year of legalization, 2013, compared to the last full year of marijuana prohibition, 2011, stands in contrast to the 14 percent increase nationwide during the same period (Table 1). Similarly, overall traffic fatality rates fell in Colorado and Washington from 2011 to 2013 slightly more than they did nationwide, indicating no new marijuana danger.
Table 1. Drivers in fatal crashes, percent drug-tested and testing positive for marijuana
Colorado
Washington
United States
2011
2012
2013
2011
2012
2013
2011
2012
2013
Total drivers in fatal crashes
587
632
627
606
591
593
43,840
45,664
44,574
Drivers tested for drugs
257
236
242
339
340
297
16,970
17,459
15,836
Percent tested
44%
37%
39%
56%
58%
50%
39%
38%
36%
Of those tested for drugs:
Tested positive for marijuana
44
29
30
42
43
28
1,641
1,882
1,748
Percent positive for marijuana
17.1% 12.3% 12.4% 12.4% 12.6% 9.4% 9.7% 10.8% 11.0%Change, 2013 vs 2011
-28%
-24%
+14%
Source: Fatality Analysis Reporting System (FARS, 2015). FARS is a U.S. Department of Transportation web-based query system reporting factors in every traffic accident involving at least one fatality in the United States.
The problem in evaluating these numbers is that only around four in 10 drivers in fatal crashes in Colorado, and a little more than half in Washington, are tested for drugs. Strangely, given the need for information on the effects of marijuana reform, both states drug-tested a substantially lower proportion of drivers in 2013 than in 2011; still, their tested proportions were above the national average.
It remains surprising and dismaying that marijuana reform in Washington and Colorado is being met with reduced instead of increased efforts to evaluate its more vital effects, and that across the country, so few drivers in fatal traffic accidents — the group that should be most likely to be tested for drugs — actually are tested. Given new Centers for Disease Control figures showing another surge in drug abuse fatalities to nearly 46,000 nationally in 2013 (the subject of an upcoming blog), the need to reform laws criminalizing milder drugs like marijuana is even more imperative to concentrate resources on treatment-based approaches to more destructive drugs of abuse, like pharmaceuticals, heroin, cocaine, methamphetamine, and alcohol. Science-based reform requires much better information than is now being provided.