The DMV has released a report that finds Ignition Interlock devices do not work on deterring DUIs - generally.  Since July 1, 2010, the pilot program has required that anyone convicted of a DUI in Alameda, Los Angeles, Sacramento or Tulare counties install an ignition interlock device on any car they own or operate.

The DMV is conducting another study to determine if the pilot program has any specific deterrence effects.

For more information you can read the report here:

DMV IGNITION INTERLOCK REPORT