In 2012, the States of Washington and Colorado legalized the consumption of marijuana for recreational purposes. One of the components of the legislation in Washington State included provisions on driving under the influence of marijuana. These new laws place marijuana under the same regulatory scheme as alcohol, which I believe is a mistake, particularly for the offense of driving under the influence.
Washington State defines the offense of driving under the influence of marijuana under 46.61.502, which establishes a legal limit similar to alcohol utilizing the concentration of delta-9 tetrahydrocannabinol (THC) content per milliliter of a person’s whole blood. (THC is the chemical compound associated primarily with the psychoactive effects of ingesting cannabis.)
According to 46.61.502(1)(b), if within two hours of operating a vehicle, your blood test comes back with a THC concentration of 5.0 ng/ml or higher (nanograms per milliliter of whole blood), you have violated the statute and committed a DUI.
After smoking, THC levels rise to approximately 150 ng/ml blood. Within the first hour these levels drop dramatically to about 15, and continues on a steady decline. On average, it takes between two and a half and three hours after smoking for your blood levels to return to the legal limit.
Follow the Law
Now, I know what you may be thinking, The National Highway Traffic Safety Association just recently stated in February of this year that with regard to psychoactive drugs, “At the current time, specific drug concentration levels cannot be reliably equated with a specific degree of driver impairment.” And this is where I believe these new laws will need to be changed because regulating marijuana like it is alcohol.
While having a BAC of 0.05% or higher increases your chances of being in a collision by almost six, consuming marijuana has no statistical influence positively or negatively with your risk of being involved in an automobile crash (when adjusting for the drivers, age, gender, race, and consumption of alcohol). But that’s not to say that marijuana could not impair your driving; just that the presence of THC in your system does not correlate with impairment the way that alcohol blood concentration levels do.
But regardless of whether marijuana does impair your driving, it is important to always follow the law.
How Can I Follow the Law If I’m Always Above the Legal Limit?
The NHTSA study notes that “Most psychoactive drugs are chemically complex molecules, whose absorption, action, and elimination from the body are difficult to predict, and considerable differences exist between individuals with regard to the rates with which these processes occur. Alcohol, in comparison, is more predictable. A strong relationship between alcohol concentration and impairment has been established, as has the correlation between alcohol concentration and crash risk.”
Marijuana does not metabolize in a predictable manner like alcohol. Moreover, if you regularly consume marijuana, your blood levels may be in excess of the limit because marijuana stays in your bloodstream long after you have consumed it. How you consume your marijuana will also affect your blood concentration levels and impairment. So it’s important to always monitor your consumption.
The new DUI laws for marijuana will likely affect innocent drivers, which will certainly be the subject of litigation for years to come if the legislature continues to treat marijuana as alcohol.