DUI/Impaired Driving

Impaired driving is a leading factor in Washington traffic deaths. The Washington State Patrol’s Impaired Driving Section runs the agency’s Evidential Breath Test, Drug Evaluation and Classification, Standardized Field Sobriety Testing and Ignition Interlock Programs, and coordinates deployment of the Mobile Impaired Driving Unit. To learn more about the services they provide, please visit the pages listed below.

Evidential Breath Testing

The Breath Test Program (BTP) manages, maintains, and certifies the calibration of more than 220 evidentiary breath testing instruments in the state. Here you can view public records (including Datamaster database records), signed affidavits and repair certifications, standard operating procedures, and curriculum vitae. To access these records, click here.

Drug Evaluation and Classification

The Washington State Patrol coordinates the Drug Recognition Experts program for the State of Washington. A Drug Recognition Expert is a law enforcement officer trained to recognize impairment in drivers under the influence of drugs other than, or in addition to, alcohol. Many law enforcement agencies in the state of Washington participate in the Drug Recognition Expert program. Forms and manuals related to the Drug Recognition Experts are available here.

Ignition Interlock

The Washington State Patrol regulates the ignition interlock industry, through legislative mandate, and certifies ignition interlock manufacturers to conduct business in Washington. This program also monitors ignition interlock installers by conducting annual onsite audits to verify the devices are being calibrated and installed under state guidelines. Citizens, required to have the device installed, are subject to random compliance checks and review of their individual device’s database. To visit our Ignition Interlock Program page, please click here.

Mobile Impaired Driving Unit

The Mobile Impaired Unit is a self-contained 36-foot motorhome that has been turned into a mobile DUI processing center and incident command post. When requested, the MIDU travels across the state in support of law enforcement efforts during DUI emphasis patrols or to emergency incidents such as wild land fires or other natural disasters. It’s a full service police station on wheels. For questions or to request the MIDU for an event, please contact the MIDU State Coordinator via email: MIDU@wsp.wa.gov.