Mandating interlocks for fully revoked offenders: the New Mexico experience

Area of Science:

• Forensic Science
• Public Health
• Criminology

Background:

• In New Mexico, ignition interlocks were an optional judicial sanction for repeat driving-while-impaired (DWI) offenders between 1999 and 2002.
• This study examines the effectiveness of ignition interlocks in reducing DWI recidivism among convicted offenders.

Purpose of the Study:

• To evaluate the impact of ignition interlock devices on DWI recidivism rates.
• To compare recidivism between offenders who used ignition interlocks and those who did not.

Main Methods:

• A cohort of 437 second and third DWI offenders who installed ignition interlocks was compared to a control group of 12,554 non-interlock offenders.
• Data on DWI arrests and convictions were obtained from the Motor Vehicle Department's Citation Tracking System.
• Survival analysis and Cox proportional hazard regression were employed to analyze recidivism during and after interlock installation.

Main Results:

• Ignition interlock users showed a 65% reduction in DWI rearrest rates during the installation period compared to the control group.
• No significant difference in recidivism was observed between groups in the 3-year period after interlock removal.
• Over a 4-year follow-up, interlock users maintained lower overall recidivism rates than non-users.

Conclusions:

• Ignition interlocks are effective in reducing DWI recidivism while installed.
• The findings are consistent with previous research on ignition interlock effectiveness.