Review of Ignition Interlock Device Compliance and Monitoring

March 2025

Zack Freeman, team lead
Ryan McCord, audit director | Eric Thomas, legislative auditor

Drivers must install ignition interlock devices when required by law

State law requires drivers convicted of driving under the influence or related charges to install an ignition interlock device (IID) in their vehicle. In some cases, courts may require drivers to install an IID as a condition of release prior to conviction.

An IID is an alcohol monitoring system that is wired into a vehicle’s ignition. The device prevents a vehicle from starting if the driver’s breath alcohol concentration is 0.02 or higher. A driver with an IID requirement must pay to lease, install, and service the device.

Five IID manufacturers are approved to do business in Washington. Certified technicians must install the devices at designated interlock service centers. State rules require manufacturers to ensure that a driver has access to a service center within a 75-mile radius of their home. There are more than 130 active service centers.

Multiple entities are responsible for administering the ignition interlock program

• Courts may require a driver to install an IID as a condition of release before trial or following a conviction.
• Department of Licensing manages ignition interlock requirements. It issues ignition interlock licenses, verifies device installation, and provides financial assistance to low-income drivers.
• Washington State Patrol certifies IID manufacturers and the technicians and service centers that install them.

Study scope

The 2024 Legislature directed the Joint Legislative Audit and Review Committee (JLARC) to review IID compliance and oversight. This study will focus on driver compliance with IID installation requirements and on judicial and agency oversight of those requirements. This study will not address broader equity factors in the criminal justice system.

This study will address the following questions

Study questions define the scope of the audit, based on the study mandate. They reflect preliminary outreach, research, and analysis of potential racial equity considerations per RCW 44.28.076.

1. What percentage of individuals with an ignition interlock device requirement have one installed in their vehicle?
   1. Do installation rates vary by race or ethnicity?
2. What factors affect compliance with ignition interlock installation requirements?
3. How effectively do state and local agencies monitor and enforce ignition interlock device requirements?
4. How do ignition interlock device compliance and enforcement in Washington compare to other states?

What's next

• Preliminary Report: December 2025
• Proposed Final Report: January 2026

Study team

Zack Freeman, team lead, (360) 786-5179
Aaron Cavin, research analyst, (360) 786-5194
Vivien Chen, research analyst, (360) 786-5190
Sydney Romero, research analyst, (360) 786-7297