Do states always require installing an ignition interlock device after a DUI/DWI conviction? After a second or subsequent substance-related conviction, drivers must install an IID in any vehicle they operate. Most states require both an SR-22 (or FR-44) insurance filing and ignition interlock installation and as a condition for license reinstatement.
Drivers may not need to install an IID after a first DUI/DWI violation unless the situation warrants it. Each state makes a determination based on the circumstances of each case.
