Sensi: Driving While Impaired

Leland Rucker is the senior editor at Sensi Magazine and he joins us on Thursday mornings at 8.20am to talk about the latest news in cannabis.



A new state Department of Transportation study on impaired driving found that the number of highway deaths involving Colorado drivers who had marijuana in their system was up again in 2017. But traffic fatalities in which drivers had legally impaired marijuana in their bloodstream dropped from 52 in 2016 to 35 last year.


That doesn’t make sense unless you realize that marijuana can remain in the bloodstream for a long period, so a positive blood test may not mean a driver was impaired. The study noted: “The presence of a cannabinoid does not necessarily indicate recent use of marijuana or impairment.” Colorado law says that drivers with five nanograms of active tetrahydrocannabinol (THC) in a milliliter of their blood can be prosecuted for driving under the influence of marijuana, although it doesn’t mean they will be prosecuted.



The number of fatalities involving positive tests for marijuana has nearly doubled since recreational legalization in 2014, from 75 that year to 125 in 2016 and 139 last year. And the study found that people are driving around with more than one drug. Deaths where drivers tested positive for cannabis, any alcohol and other drugs rose from eight in 2016 to 25 last year.


The report also found that drunken driving deaths had increased again. Twenty-six percent of those killed in crashes, or 171 people, had blood alcohol content of 0.08 percent or greater, Colorado’s drunken driving limit, compared to 161 in 2016 and 151 in 2015. Meanwhile, traffic deaths generally continued to increase on state roads, going from 546 in 2015 to 608 in 2016 and 648 last year.


CDOT spokesman Sam Cole said the department considers the number of deaths in which the driver was marijuana-impaired under state law to be the most reliable indicator of its impact on the highways. By that measure, marijuana-related deaths are clearly down.


“Presence does not indicate impairment,” he said. At the same time, “two years does not make a trend.”


Takeaway: Don’t mix cannabis and alcohol and drive, under any circumstances.

Read the CDOT report on impaired driving: