Based on federal and state data beginning in 2013, drivers in fatal crashes are increasingly testing positive for marijuana. A recent Denver Post report analyzed information from coroners to determine the impact that marijuana legalization has had on roadway safety. Of the fatally injured drivers tested in 2016, roughly 10 had a concentration level at least five times the legal limit. The majority of surviving drivers that tested positive had levels indicating recent usage. Retail marijuana sales to adults started in 2014 and the Colorado Department of Transportation (CDOT) and the National Highway Transportation Safety Association (NHTSA) have worked to obtain data on how roadway safety has been impacted.
John Jackson, Greenwood Village's Chief of Police, says the state's marijuana legalization creates a huge safety problem with injuries, fatalities and property damage. NHTSA data from 2013-2016 reflected a 40% increase in the traffic fatalities across the state, rising from 627 to 880. During this period it was determined that alcohol involvement rose 17% and marijuana involvement rose 145%. The report did not indicate whether requirements for or frequency of testing for marijuana during this period changed. Coroners are not required to test for marijuana in fatal accident victims and many agencies stated that if the driver's alcohol level is beyond the limit, they do not test for further drugs.
The NHTSA uses a Fatality Analysis Reporting System (FARS). Proponents of the marijuana industry say FARS data is inaccurate and is not able to truly link marijuana to fatal crashes. Taylor West, of the National Cannabis Industry Association, says THC (unlike alcohol) can remain detectable in the blood for days—long after impairment. West says that consumption has risen since the product was legalized; however, these tests are not indicative of whether they were high when they were driving. The Substance Abuse & Mental Health Services Administration says respondents that had used marijuana in the last 30 days rose 42% between 2013 and 2015, but the Colorado Department of Health's data for this time period showed a much slower increase.
Kristi Kelly, Director of The Marijuana Industry Group, says alcohol has been scientifically reviewed and tested for decades. She explains that the data is well documented regarding the effect that alcohol has on a driver. She points to a lack of hard evidence that truly confirms the decline in the cognitive ability of a marijuana user. With studies underway at the federal and state levels, this data should emerge in the coming years.
Colorado and Washington are two states who legalized marijuana around the same time and their trends are notably similar. Washington's Traffic Safety Commission says that impairment from drugs has surpassed alcohol. Yet, coroners and law enforcement both agree that determining the percentage of drivers with active THC levels is challenging because so few are actually tested. In 2016, Colorado drivers with involvement in fatal collisions were tested roughly half of the time. Lt. Robert Rock of the Denver Police Department explained that alcohol is the first test conducted, and if the result is over the limit, the testing is finished. Chief Jackson affirmed this by saying that in DUI situations, once a driver is over the limit for alcohol, the testing is concluded.
CDOT reports show that the overall number of traffic fatalities is rising, not just those involving marijuana. Their data suggests that the use of mobile devices among drivers is also a key cause in fatalities and those involving pedestrians. CDOT is going to continue to push for more testing to truly measure the number of drivers with active THC levels and develop more definitive data. The current THC limit for impairment is measured at 5ng/nL, and a recent Denver Post report showed drivers were found to have levels well over 24ng/mL.
The vast majority of reports suggest a strong correlation between marijuana use and traffic fatalities; however, the specific percentages are widely subject to speculation. With the relatively new efforts to more consistently test for marijuana, it is very likely that the quality of the data will significantly improve. In the next segment, we will transition to public perception and attitudes toward marijuana impairment.