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CARS-DUI Assessment Project

Computerized Assessment and Referral System (CARS) is proud to announce the development and launch of a ground-breaking assessment instrument that will assist practitioners in making appropriate sentencing, supervision, and treatment decisions. After years of rigorous study and pilot testing, the Computerized Assessment and Referral System (CARS) is now available, free of cost, to interested practitioners and agencies. To download the assessment, access the CARS Training Center.

Why is CARS needed?

Collective efforts over 35 years has led to a 51% decrease in drunk driving. However, drunk driving remains a stubborn problem that claimed 10,265 lives in 2015 (NHTSA, 2016). Repeat DUI offenders, in particular, are highly resistant to changing their behavior despite previous sanctions, treatment, or education efforts. Research has found that these offenders commonly suffer from a number of mental health disorders (e.g., anxiety disorders, post-traumatic stress disorder, depression, bipolar disorder, conduct disorder) in addition to their substance use issues. In one study, in addition to a lifetime alcohol disorder, 41% of the participants had a drug-related disorder and 45% had a major mental disorder that was not alcohol or drug-related.

The basis for the Computerized Assessment and Referral System was the recognition of the high level of psychiatric co-morbidity in DUI populations. Historically, treatment of this offender population has consisted of alcohol education or interventions that focus solely on alcohol or other substance use disorders. Screening for mental health issues in addition to substance use is not always available or performed within DUI treatment programs. CARS was developed to fill this void as its primary purpose is to identify mental health issues that might influence DUI behaviors, facilitate additional treatment for those issues and possibly reduce future recidivism.

Developed by the Division on Addiction, Cambridge Health Alliance, a teaching affiliate of Harvard Medical School, with initial support by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and ongoing funding from, CARS is a standardized mental health assessment tool, based on the World Health Organization’s Composite International Diagnostic Interview (or CIDI), that runs on free, open source software.

How does CARS work?

  • Asks about signs and symptoms of mental health issues both within the past year and lifetime.
  • Identifies specific mental health disorders for which an offender is at-risk.
  • Generates a report that informs the user about a client’s recidivism risk level and treatment needs and provides appropriate ZIP code based referrals.
  • Can be used in three formats:
    • CARS screener (15-20 minutes)
    • Self-administered CARS screener (15-40 minutes)
    • Full CARS assessment (1-2 hours)

Why is CARS revolutionary?

  • Developed specifically for a DUI offender population;
  • Provides immediate diagnostic information for up to 15 major psychiatric disorders;
  • Provides geographically and individually targeted referrals to appropriate treatment services;
  • Generates user-friendly reports at the click of a button;
  • Informs supervision and treatment decisions;
  • Runs on free open source software; and,
  • Can be used by non-clinicians. supports the use of comprehensive assessment for substance use and mental health disorders among the DUI offender population as well as referrals to appropriate treatment interventions tailored to individual risks and needs.

CARS has received widespread support from the Governor’s Highway Safety Association, Emergency Medicine Foundation, Cambridge Health Alliance, Harvard Medical School, and Harvard School of Public Health.

CARS randomized control trials

Following the 2013 usability trials, a full implementation study was completed in 2015 among first offenders and repeat offenders in two Massachusetts-based DUI treatment programs. The randomized control trials (RCTs) assessed the usability of the comprehensive CARS instrument along with two shorter versions (i.e., screeners). Data analyses from these implementation trials validated the self-administered CARS screener, interviewer-administered CARS screener, and comprehensive CARS assessment as effective instruments for screening and assessing impaired drivers. The RCTs also found:

  • Continued evidence of co-morbidity in the repeat DUI population, particularly anxiety-related disorders.
  • Full CARS provides diagnostic information.
  • Screening results did not differ significantly by condition, with the exception of conduct disorder among DUI offenders in the self-administered trial setting.
  • CARS screener does a very good job of identifying substance use disorders.
  • Results from the self-administered screener do not differ fundamentally from those for the interviewer-administered screener.

In October 2015, Dr. Howard Shaffer, lead researcher and the Dr. Morris E. Chafetz Professor in Psychiatry in the Field of Behavioral Sciences at Harvard Medical School and Dr. Sarah Nelson, Associate Director of Research, Harvard Medical School, Division on Addiction, The Cambridge Health Alliance, presented the preliminary results of the implementation trials of the CARS tool to the National Highway Traffic Safety Administration (NHTSA) and the National Institute on Alcohol Abuse and Alcoholism (NIAAA). More recent results were presented at the National Association of Drug Court Professionals (NADCP) Training Conference in the summer of 2016:

CARS presentation at NADCP Annual Training Conference (June 2016)

CARS implementation pilots

In 2016, supported the implementation of CARS at six pilot sites across the country. The sites were chosen after a thorough selection process which sought to identify programs that represent a variety of different criminal justice models (e.g., DUI Courts, traditional probation, intensive supervision, etc.) and have an established history of utilizing innovative practices. Also of importance, the following sites offered an opportunity to implement CARS in both urban and rural locales:

  • IMPACT DWI Program (Milwaukee, WI)
  • Isanti County probation; Judge James Dehn (Cambridge, MN)
  • Lackawanna/Susquehanna Office of Drug and Alcohol Programs; Judge Michael Barrasse (Scranton, PA)
  • Laramie County DUI Court (Cheyenne, WY)
  • San Joaquin County DUI Monitoring Court; Judge Richard Vlavianos (Stockton, CA)
  • South St. Louis County DWI Court and probation; Judge Shaun Floerke (Duluth, MN)

The information collected from the pilots has been instrumental in identifying ways to improve the efficiency of the CARS assessment and will inform the development of online training materials. A report that summarizes the experience of the pilot sites and provides CARS implementation recommendations is now available.

Next Steps

CARS is now available for national distribution; researchers will continue to collect empirical data to link specific mental health profiles to recidivism risk.

Currently, CARS identifies DUI risk based on known predictors from the research literature. Expansion of the use of CARS program will enable data to be collected that will allow researchers to modify the risk scale using empirical data to link specific mental health profiles to recidivism risk. Additionally, moving beyond post-conviction DUI programs – time between sentencing and DUI treatment – would represent an earlier assessment and intervention opportunity among at-risk populations.

Another exciting development that will occur in 2017 is the piloting of CARS among the general population. This year, is partnering with the Emergency Medicine Foundation to integrate CARS within two emergency departments.


To view or download a webinar that describes the development and implementation of CARS and includes a live demonstration of the software used, please visit this page.

For more information, access the full CARS synopsis or contact Erin Holmes, Director of Traffic Safety at [email protected]