Data released by the Washington State Patrol for the first six months of 2013 show that a greater number of drivers have turned up positive for THC in the blood following a traffic stop for suspected impaired driving. However, as media sounds the alarm on the rise of “stoned driving” following legalization of marijuana, they miss four important facts:
“Legally stoned” driving is on the decline.
From 2009-2012, Washington State Patrol (WSP) made about 20,000 stops each year for suspected impaired driving and WSP is on pace to hit that same number this year. So, it doesn’t appear that cops are seeing more impaired drivers on the road.
Of those 20,000 stops, cops ordered a blood test about one-quarter of the time, about 4,800 tests in 2009 rising to about 5,300 tests in 2012. Of those tests, about one-fifth of the time they came back positive for THC. This year, however, tests are coming back positive for THC about 27% of the time. The media have thereby declared there’s a great rise in “stoned driving” because 745 tests came back THC-positive over six months when the average is about 1,000 over a year.
By law, “stoned driving” is now defined as being over 5 nanograms of THC per milliliter of blood (5ng). In 2009-2012, all 1,000 of those THC-positive tests -- over or under 5ng -- was a “stoned driver.” In 2013, those drivers testing below 5ng are “under the limit.” Of those 745 THC-positives, only 420 (yes, really) of the drivers were “over the limit.” That’s on pace for 840 “legally stoned” drivers, far less than the average 1,000 per year from the previous four years. It also means 325 of those THC-positive drivers were “under the limit” and have a DUI defense they didn’t have before legalization.
But still, aren’t 745 THC-positives on pace for 1,490 over the year, an almost 50% increase from previous years? Yes, but the proportion of those positives that are “legally stoned” is down. In 2012, 61.6% of the 988 THC-positives were over 5ng; this year, 56.4% of the 745 THC-positives are over the limit. Part of the reason we are seeing more tests showing “stoned drivers” is because…
Cops are focusing more on “stoned drivers.”
This year, WSP is on pace to conduct almost 200 more blood tests than the year before. Each year since 2009, the number of tests ordered has increased by about 167. Now that there is a per se 5ng standard for “stoned driving,” cops have more incentive to go get a blood test in a marijuana case. Cops are also being trained to focus more on the behaviors indicative of “stoned driving.”
Just because you’re catching more fish that doesn’t mean there are actually more fish. You may just be using bigger nets in better locations for longer periods of time. It’s illustrative to remember that WSP tells us they’re still making about the same number of stops for suspected impaired driving, so all the data tell us are cops are more likely to suspect and test for marijuana now than before legalization. So not only have we not seen an increase in impaired driving, but…
Impaired driving fatalities are plummeting.
The Washington Traffic Safety Commission keeps records on how many people died on Washington roads as part of its “Target: Zero” program. In 2009, 169 people died in an alcohol-related traffic fatality and 140 died from a drug-related traffic fatality. Those figures have declined every year since and in 2013, through six months the state is on pace for 88 alcohol fatalities and 80 drug-related fatalities. Drug fatalities include all drugs, not just THC; however, THC and alcohol are the only drugs for which Washington State has a set limit that proves you were too impaired to drive, and as we all know…
A blood test for THC does not tell us someone is impaired.
This is why we put “stoned driving” in quotes, because a THC blood test tells us nothing about how impaired a toker actually is. Alcohol is reliably metabolized by the body and its concentration in the blood directly relates to impairment. But marijuana is metabolized differently by everybody and frequent users develop a tolerance to impairment. A newbie might be totally stoned at 5ng whereas a daily toker might wake up and be completely clear-headed at over 5ng. It would be nice if the media would remind its audience of these scientific facts when reporting on “stoned driving.”
In order to get the blood test, police must have made an arrest for DUI based on observations of the driver. One might argue that if the toker was driving so poorly as to get pulled over, maybe that 5ng reading is showing he was too stoned to drive. However, one might also argue that a cop who hates tokers and now can’t bust them for possession would make up excuses to pull over suspected tokers, hoping for a 5ng reading.
For now, it seems like the worst fears of both sides have not come to fruition. Where cops predicted an epidemic of “stoned driving” and mayhem on the roads, it appears they’re making the same number of impairment stops and deaths are declining. Where No on I-502 predicted DUIs for unimpaired tokers would be replacing marijuana possession arrests, it looks like fewer of the positive tests will actually be over the new legal limit and 10,000 former possession arrests will not become 10,000 DUI cases.
"Radical" Russ Belville is the host of "The Russ Belville Show."