It's official (or mostly). Washington voters have decided to legalize recreational marijuana use by approving Initiative 502, but a legal battle with the federal government still looms. Perhaps what is most interesting from a DUI perspective is that the approved measure, for the first time in Washington state, sets a limit for THC impairment.
Included in the initiative is a DUI charge provision, which makes it "per se" illegal to drive with a blood-THC level greater than five nanograms per milliliter of blood. This means that drivers with a higher blood-THC level will be presumed to be impaired. However, the science behind marijuana levels and impairment is considered controversial. One Seattle driver charged with DUI was recently acquitted, despite a positive test, for these reasons.
Although DUI charges are commonly associated with alcohol impairment, driving under the influence of drugs can also result in DUI allegations. In addition, having a valid prescription is not considered a defense against drugged driving charges. This means that even those with a medical marijuana card can be charged with DUI if their blood-THC level is found to be over the legal limit.
So how can individuals self-measure those nanograms to avoid a DUI? Well, different types of marijuana have different strengths, so it's tricky to measure impairment the way a cop would. Basically, five nanograms of blood-THC can be thought of as a blood-alcohol reading of 0.05 percent, which is three hundredths of a point lower than the driving limit for alcohol. Also, critics say the ambiguity of the science could lead to widespread DUI charges.
While many Seattle residents undoubtedly welcome the passage of I-502, every smoker of marijuana needs to be aware of the applicable laws and rights. Furthermore, people accused of drugged driving will need a strong legal advocate to fight the charges.
Source: The Seattle Times, "I-502 raises question about how much pot is too much for drivers," Oct. 27, 2012
Source: The Washington Post, "Legal battle looms over marijuana initiatives," Sari Horwitz, Nov. 7, 2012