When will my ignition interlock notify the police?
Washington Administrative Code regulations provide that when an ignition interlock is required, it must be set up so that the vehicle won't start unless you first blow into the device and "pass" (usually a reading not more than .025). Also required is a "rolling retest" within the first ten minutes and within every hour thereafter while the vehicle is in operation, usually with the same .025 "pass" level. By regulation, the device must "notify the police" if these tests are failed.
How are the police notified?
The code (WAC 204-50-110) states in part as follows: "...acceptable forms of notification are repeated honking of the vehicle's horn, repeated flashing of the vehicle's headlamps, or the wailing of a small siren." This occurs until the engine is tuned off or a "pass" reading is obtained. Because interlocks are not specific for ethyl alcohol, false positives can result. No Washington State reported case has determined whether a police detention of a car based upon the daylight flashing of headlights is legal.