Driving under the influence of marijuana is a crime in Washington. This article explains the penalties imposed for DUI violations, but other laws regarding marijuana possession may also apply to drivers and passengers. Also, while Washington allows medical marijuana use under limited circumstances, it is still a crime to drive after such use. (Wa. Rev. Code Ann. § 46.61.502(2).)
For information about how Washington treats marijuana possession, sale, and manufacture, see Washington Marijuana Laws.
To learn about Washington's medical marijuana laws, see Washington Medical Marijuana Laws.
It is illegal to drive a vehicle while under the influence of marijuana, alcohol, other drugs, or a combination of substances. When alcohol is involved, a blood alcohol level of 0.08 percent of the driver's blood, by volume, will conclusively establish that the driver is under the influence (if the level is less, the prosecutor can still point to the driver's actions to prove that he was under the influence).(Wa. Rev. Code Ann. § 46.61.502.)
When marijuana is involved, a blood THC level of 5 nanograms will establish that the driver was under the influence.
Penalties vary according to whether the offense is a first of subsequent conviction. The judge may also order the defendant to use an ignition interlock device after the applicable period of license suspension is over. A defendant with a second or subsequent conviction may also face vehicle forfeiture.
If you have been charged with a marijuana-related driving offense, consult an experienced criminal defense attorney. While the penalties and consequences of a marijuana charge are governed by statutory law, only a local criminal defense attorney can tell you how cases like yours tend to be handled by prosecutors and judges in your courthouse.