The Drug and Alcohol Impaired Driver is a guide for police enforcement of DUI laws. This book is helpful for police from the command level to the patrol officer. The author, a retired judge, explains how to employ stop, search and arrest and their legal limits in a clear and understandable way. The book presents a description of hundreds of drugs (both legal and illegal) and their effects on driving. A list of federally controlled substances is also included for easy reference. The latest developments on the legalization of marijuana and new research on the risk of driving under the influence of marijuana are included. It explains the legislative approaches states use for DUI enforcement. Strategies for enforcement, investigative techniques and tips for effective in-court testimony are covered. This book is an exceptionally useful resource for the classroom, field use and command decisions in enforcement.