The Tracometer as an Intoxication Warning Device

Abstract

An experiment was conducted to investigate the feasibility of developing an in-vehicle skill-based drunk driver detection and deterrence system. The experiment compared two well-developed psychomotor test devices, the Tracometer and the Critical Tracking Task (CTT), for their ability to detect alcohol intoxication. The Tracometer employed a pursuit tracking task whereas the CTT employed a compensatory tracking task. Twenty male subjects, aged 19 − 30 were trained on the Tracometer and the CTT over a three day period. On two subsequent test days, they were treated with either placebo or alcoholic beverages designed to bring their peak Blood Alcohol Concentration (BAC) to 1.2% (1200 mg/L). On each day, the subjects were tested once before treatment and six times after treatment at hourly intervals as their BAC levels declined. The results indicate that the Tracometer was more sensitive than the CTT to the the effects of alcohol over a wide range of BAC levels. At a BAC level of .08%, performance on the Tracometer deteriorated by 16% whereas performance on the CTT deteriorated by only 7%. Using optimized pass/fail protocols, the Tracometer failed 60% of subjects with BAC in the range .08–1.0%, whereas the CTT failed 34%. At BAC levels above 1.0%, the Tracometer failed about 85% whereas the CTT failed 40%. These results clearly illustrate the potential of the Tracometer as a test of alcohol intoxication. Although the impetus behind the study was the development of drunk-driving countermeasures, the technology can be easily extended to include other applications.