Novice drivers’ performance after different alcohol dosages and placebo in the divided-attention steering simulator (DASS)

Rationale The divided-attention steering simulator (DASS) is designed to measure lane-keeping (i.e., a tracking task using a steering wheel) while performing a secondary visual task (responding to digits that appear in the corners of the computer screen). Some studies have already used the DASS, but the magnitude of impairment is difficult to interpret because reference values are lacking. Objective To examine the magnitude of impairment after administration of four different dosages of alcohol and placebo. Materials and methods Thirty-two healthy young adults participated in this randomized, single-blind crossover trial. Subjects received alcohol to gain a blood alcohol concentration (BAC) of 0.02%, 0.05%, 0.08%, and 0.10% or alcohol–placebo. Sixteen subjects performed a 30-min test in DASS (dual-task condition). Outcome measures were steering error, reaction time, and percentage of errors. Sixteen other subjects performed the test without performing the secondary peripheral task (single-task condition). Results Twenty-eight subjects (novice drivers; drivers’ license up to 5 years) were included in the analyses. Dose-dependent impairment was found in both the single-task condition ( F (4,11) = 10.86, p