Washingtonians can receive a DUI for driving while high, according to a recent Washington state Supreme Court decision that upholds the state’s decade-old law regulating marijuana use behind the wheel of a car.

All nine justices rejected the argument that a 2017 DUI was based on an arbitrary and vague standard for THC levels in the blood. Although the justices acknowledged that the correlation between THC levels and impairment is challenging to pinpoint, they found that blood measurements nevertheless provide a useful and constitutionally acceptable measurement.

For a free consultation about a felony or misdemeanor criminal charge, or traffic violation, call (360) 736-1301.

According to the Washington State Trooper making the arrest, the driver said he had smoked “half a day” earlier but that he no longer felt impaired. After performing several field tests, the trooper arrested the driver on suspicion of DUI.

A test later showed Fraser had a THC blood concentration of 9.4 nanograms per milliliter, with a margin of error of 2.5. That put his THC blood concentration above the state’s 5 ng/ml limit.

According to RCW 46.25.110, notwithstanding any other provision of Title 46 RCW, a person may not drive, operate, or be in physical control of a commercial motor vehicle while having alcohol or THC in his or her system.(2) Law enforcement or appropriate officials shall issue an out-of-service order valid for twenty-four hours against a person who drives, operates, or is in physical control of a commercial motor vehicle while having alcohol or THC in his or her system or who refuses to take a test to determine his or her alcohol content or THC concentration as provided by RCW 46.25.120.

The driver argued in court that the limit was not correlated to any real measure of impairment and was therefore arbitrary, vague and unconstitutional. He backed his opinion with testimony from a doctor who said the effect of a given level of THC can vary significantly from person to person,  depending on body fat and frequency of cannabis use.

The justices agreed that impairment standards based solely on THC blood concentration can’t be generalized to the entire population but disagreed that meant the state’s standard was vague or arbitrary.

That’s because marijuana became legal in Washington via a people’s initiative, so the burden for proving the standard unconstitutional is high. Additionally, for both alcohol and marijuana, the standard is based on perceived impairment or blood levels.

And while driving and cannabis use are both legal, neither is a right, the justices said. The impairment caused by 5 ng/ml of THC in the blood may vary, but the limit serves its purpose by discouraging drivers from taking to the roads after using marijuana.

FREE Consultations in Centralia or Olympia

For a free consultation with our attorneys in Centralia or Olympia about a felony, misdemeanor, or traffic violation, call Jakob McGhie at (360) 736-1301 or visit Centralialaw.com.