Washington’s drugged driving law is located at Revised Code of Washington Section 46.61.502. It prohibits driving while “under the influence of or affected by intoxicating liquor, marijuana, or any drug."
In other words, in Washington it’s a crime to drive while under the influence of a drug. No blood testing standard is established in Washington – that is, there is no fixed amount of drugs within the blood system that determines conviction. Whether a driver is impaired is determined on a case-by-case basis and at the discretion of the prosecutor. In addition the statute cited above, Washington also has a law that prohibits driving a vehicle if it “endangers or is likely to endanger any person or property, and (the driver) exhibits the effects of having consumed an illegal drug.”
Washington’s drugged driving law is directed at the prohibition of any controlled drug (as defined in Washington Code § 318-B:1). (A listing of controlled substances regulated by federal law are found at the Drug Enforcement Administration website.) It’s not an acceptable defense to a drugged driving charge to claim that the driver is legally entitled to use the controlled substance.
A driver arrested for drugged driving in Washington will be charged with driving under the influence and subject to DUI penalties. A conviction for drugged driving will be considered as a prior offense for purposes of calculating punishment regardless of whether a subsequent offense is due to alcohol or drugs. Read more about Washington’s DUI laws.
Yes, there is an implied consent rule for blood and urine testing. The refusal to take the test can be admitted into evidence against the driver.