Assessing driver status: a demonstration experiment on the road.

Twenty subjects completed an on-the-road experiment that consisted of two parts on two separate days. One was a one-hour driving test under the influence of alcohol (BAC less than = 0.05%), the second a two-and-a-half-hour driving test under vigilance conditions. Impairment of driving performance was measured in a car-following test as well as in a standard driving test. Changes in relevant physiological parameters, such as ECG and EEG, reflected changes in driver status and predicted driving performance impairment.