Drunk and drugged driving laws in Washington

By the end of this topic you can

• You can state the alcohol and THC limits for drivers 21 and over.
• You can explain Washington's lower limits for drivers under 21.
• You can describe what implied consent means and what happens if you refuse a breath test.
• You can store alcohol and cannabis legally in a vehicle.
• You can plan a safe way home that does not involve impaired driving.

What you need to know and understand

• For drivers 21 and over, a breath or blood alcohol concentration of 0.08 or more, or a blood THC concentration of 5.00 or more, within two hours of driving is a DUI.
• You can also be convicted for driving while affected by alcohol, cannabis or any drug, even below those numbers.
• Drivers under 21 commit an offense with an alcohol concentration of 0.02 or more, or any THC above 0.00.
• By driving in Washington you are deemed to consent to a breath test when an officer has reasonable grounds.
• Refusing the breath test leads to license revocation or denial for at least one year, and the refusal can be used in court.
• A first adult test result over the limit brings a 90-day administrative suspension.
• Open alcohol and cannabis must be kept in the trunk, or an area no one sits in. The glove box does not count.

The limits, by age

Adults commit DUI with an alcohol concentration of 0.08 or more, or a THC level of 5.00 or more in the blood, measured within two hours of driving. Separately, it is DUI to drive while under the influence of or affected by alcohol, cannabis or any drug, including prescription and over-the-counter medicines.

For drivers under 21, the line is much lower: an alcohol concentration of 0.02 or more, or any THC at all above 0.00, within two hours of driving. In practice that means none.

Implied consent and license consequences

If an officer has reasonable grounds to think you are impaired, you are deemed to have agreed to a breath test. The officer must tell you about your right to refuse and to additional tests, but refusing has serious results.

• First refusal: license revoked or denied for one year.
• Adult first test over the limit: 90-day suspension (with an exception linked to a 24/7 sobriety program).
• Under 21 first test over the youth limit: 90-day suspension or denial.
• Repeat incidents within seven years: revocation of one or two years, or longer for under-21s.
• These license actions are separate from any criminal penalties a court may impose.

Keeping your car legal and your plans safe

Drinking alcohol or using cannabis in a vehicle on a public road is against the law. Opened alcohol, and cannabis that is not in a sealed package, must be stored in the trunk. In a vehicle without a trunk, use an area no one normally sits in or can reach. The glove box and console count as reachable.

Before any party, decide how you will get home: a sober driver, a ride service, transit or staying over. Coffee, cold air and food do not lower your alcohol level; only time does. Our Washington knowledge test guide notes that impairment is a focus topic on the test.

Common mistakes

• Believing one drink is fine for a teen driver. Under 21, 0.02 can be reached with very little alcohol.
• Assuming legal cannabis is safe to drive on. Any THC above 0.00 is an offense under 21, and impairment is illegal at any age.
• Keeping an open bottle in the glove box. It must go in the trunk.
• Thinking a cold shower or coffee sobers you up. Only time does.

Test yourself: Drunk and drugged driving laws in Washington

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• Learning to Drive in Washington State
• Moving to Washington
• Washington Knowledge Test