Washington Marijuana DUI Tests Completely Arbitrary

According to KIRO 7 News (September 3, 2018) Washington state's traffic safety commission said a recent study found most drivers between 15 and 20 years old in Washington who admitted to driving after getting high on marijuana believed doing so actually made them better drivers.

The safety commission said the most common thing they’re seeing with impaired drivers is people using two or more drugs. The most common combination is alcohol and marijuana.
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Washington’s DUI statute prohibits driving under the influence of intoxicating liquor or “any drug”. 

While an alcohol related DUI is the most common type of DUI charge, people are routinely arrested and charged with driving while being under the influence of marijuana, cocaine, methamphetamine, even prescription medications and over the counter medicines such as cough syrup and cold medicines in combination with alcohol.  It is not a defense to a DUI that one was only taking legal prescription medicines or over the counter drugs.  RCW 46.61.502 prohibits the operation of a motor vehicle while under the influence of any drug or any combination of drugs and alcohol.

On December 6, 2012, the state of Washington enacted a specific Marijuana DUI statute which proscribes driving after having a set limit of THC in the blood stream, establishes administrative licensing consequences, and provides specific funding to enforce the new law.  It is unlawful for drivers to operate a motor vehicle with .05 nanograms or greater of THC in the blood stream as determined by an authorized blood draw and analysis.  Those who are convicted under this statute will face the same DUI penalties as one convicted under the alcohol DUI statute. 

Q13 Fox News reported on July 20, 2017: When the law was enacted, Washington decided on a “per se” DUI threshold of five nanograms of THC per milliliter of blood drawn.  Drivers over that number are presumed impaired, and could be charged with a DUI.

The problem, says Washington Traffic Safety Commission research director Staci Hoff, is the number is completely arbitrary. “(The per se blood limit) wasn’t backed by scientific theories then, and it’s not backed by scientific theories now,” Hoff said.

Though the per se limit of alcohol is not perfect, .08 is a better predictor of intoxication than the limit for THC, Hoff says. That's because THC is a fat soluble drug. Chronic users who haven't smoked recently could still exhibit a level of 10 or 20 nanograms of THC per milliliter of blood.

The Washington Post had reported on May 10, 2016 that "a report by researchers at the AAA Foundation for Traffic Safety said there is no threshold that indicates when a marijuana smoker may be too impaired to drive.

“There is no reliable number that has any meaningful value in terms of predicting impairment,” said Jake Nelson, AAA’s director of traffic safety and advocacy. The AAA Foundation recommends doing away with setting legal limits for THC.

The Reason Foundation (February 22, 2018) stated "As with other non-alcohol drugs, marijuana impairment varies tremendously by individuals, even under the same dose. As with other non-alcohol drugs, marijuana does not break down in the body in a manner that correlates with psychoactivity of the drug (alcohol is the exceptional drug in this regard, not the norm), making chemical testing results [for THC] of little use in determining impairment." 

*** If you know that you have been drinking alcohol or using marijuana - Don't Drive! *** 

If you do get stopped by the police for suspicion of DUI, WA Lawyers generally advise that *** You Should Not Submit to the SFST or PBT. *** These road-side tests are voluntary and submitting to these tests cannot benefit you, but they can provide the police officer with the probable cause needed to arrest you. This includes Advanced Roadside Impaired Driving Enforcement (ARIDE) tests and similar tests conducted by a Drug Recognition Expert (DRE).