Since recreational marijuana was decriminalized in Washington State under Initiative 502 in November 2012, fatal road crashes involving drivers who recently used marijuana have doubled. The AAA (American Automobile Association) Foundation for Traffic Safety released the results of the study this month.

Researchers found that the percentage of drivers involved in fatal crashes who recently used marijuana jumped from 8% to 17% between 2013 and 2014. In 2014, one in six drivers involved in fatal crashes had recently used marijuana. Trends over time indicate that the proportion of drivers positive for THC involved in fatal crashes was generally flat before and after Initiative 502 took effect, but began increasing at a rate of about 10 percentage points per year around nine months after 502 became operational.

AAA's study noted that the results do not indicate that drivers with blood levels of detectable THC at the time of a fatal crash were in fact impaired by THC or that they were even at fault for the crash due to scientific limitations.

Despite these statistics however, AAA cautioned states against implementing legal limits that specify the maximum amount of active Tetrahydrocannabinol (THC, the chemical in cannabis responsible for most of marijuana's psychological effects) that drivers can have in their system based on the results of a blood test (Washington's law sets the legal limit for detectable levels of THC in the blood of motorists at five nanograms/milliliter.) An evaluation of data from drivers arrested for driving under the influence under laws setting a per se limit for marijuana in the blood indicated that such laws are flawed and unsupported by scientific research.

AAA noted the following problems with such laws:

No science indicates that drivers become reliably impaired at a specific level of marijuana in the blood. As Marshall Doney, AAA's President and CEO stated in a news release, “It's simply not possible today to determine whether a driver is impaired based solely on the amount of the drug in their body.”

Since marijuana is still classified as a Schedule I drug at the federal level, marijuana research is heavily regulated and controlled by the Drug Enforcement Administration. Because of the difficulty in obtaining marijuana for research, most studies are based on anecdotal evidence rather than the large double-blind studies that serve as the standard for most drug approvals in the United States.

Because marijuana can affect people differently, it is difficult to develop consistent and fair guidelines that apply across the board. Age, diet, size, gender, and metabolism, among other factors can all affect how a specified dose of marijuana affects a person.

Before a test is administered to a driver suspected to be impaired, high THC levels may drop below legal thresholds. Because it can take more than two hours to collect blood from a suspected driver due to the need to obtain a warrant and transport to a law enforcement facility, active THC blood levels can decline significantly before a test is actually performed.

Instead of setting per se limits, AAA encouraged states to use comprehensive two-component road safety laws that require both a positive test for recent use of marijuana and psychological and behavioral evidence of driver impairment.

Because of the many problems with per se limit laws, it is important to have a knowledgeable lawyer on your side defending you against a DUI charge for use of marijuana. Contact us online or via phone at 509-993-0748 for professional representation.