Detection of Illicit Drugs in Drivers

Dr. Walsh discussed his research which: documents the incidence of drug use in impaired drivers; evaluates use of on-site drug testing kits; and determines the feasibility of integrating on-site drug testing into routine police operations. For this study, subjects had to have been stopped by the police, failed roadside sobriety tests, arrested for alcohol or drug impairment and consented to a urine test. The study took place in Hillsborough County (Tampa), Florida over a 90-day period. Refusal rates were high with 28.8% refusing the breath test. Most who refused the breath test also refused to provide a urine sample (approximately 40% of those asked refused to provide the sample). Subject demographics were: 83% male, 78% Caucasian, and 87% between the ages of 20 and 50. For those providing urine samples, 266 subjects had a blood alcohol concentration (BAC) greater than .08 BAC and, of these, 77 or 29% tested positive for drugs, 22 subjects had a BAC less than .08 and, of these, 9 or 40% tested positive for drugs. Marijuana was found 54% of the time, cocaine was found 45% of the time, and opiates and amphetamines were found 2% or less of the time. Dr. Walsh concluded his remarks by saying that the prevalence of illegal drug use in drivers is a significant problem. Marijuana and cocaine, in addition to alcohol, are the principal drugs of abuse. According to Dr. Walsh, though effective, decisions regarding what thresholds to use to identify specific drugs have not been possible to date. As on-site testing technology improves, law enforcement will need to consider integrating on-site testing into routine police procedures.