Many times prosecutors will reduce a charge of DUI to Negligent Driving in the first degree.  It still will count as a prior offense if you get another DUI, but pleading guilty to Negligent Driving had one benefit: You didn’t need an interlock (assuming that you won the DOL hearing).  However, RCW 46.61.5249(4) is being amended to require: A person convicted of negligent driving in the first degree who has one or more prior offenses as defined in RCW 46.61.5055(14) within seven years shall be required, under RCW 46.20.720, to install an ignition interlock device on all vehicles operated by the person.

So, in layman terms, if you were originally charged as a DUI and either plead to a DUI or got it reduced to a reckless driving, negligent driving 1, or reckless endangerment in the past seven years and get a new conviction for a Negligent Driving in the first degree, then you have to have an interlock. The duration for the interlock could be from 1 year to 10 years, depending on any previous restrictions from the DOL.  This new law takes effect on September 1, 2011.