Impaired driving deaths represent 32% of all traffic fatalities. Alcohol, illicit drugs, prescriptions and some over-the-counter medications impact the critical divided-attention tasks necessary for safe driving. This program discusses the psychological, physiological and psychomotor effects of substances on driving skills, differences between impaired drivers and other offenders and reviews validated screening and assessment tools for impaired drivers. The program concludes with a discussion of the role law enforcement and public safety partners play in assisting in reducing recidivism.