Effects of Different Alcohol Dosages on Steering Behavior in Curve Driving

The aim of this article is to explore the detailed characteristics of steering behavior in curve driving at different alcohol dosages. Improper operation of the steering wheel is a contributing factor to increased crash risks on curves. The experiments were conducted using a driving simulator. Twenty-five licensed drivers were recruited to perform the experiments at the four different breath alcohol concentration (BrAC) levels. The steering angle (SA), steering speed (SS), steering reversal rate (SRR), and peak-to-peak value of the steering angle (PP) were used to characterize the steering behavior. The vehicle’s speed and the number of lane exceedances per kilometer were also used to examine the driving performance. The SSs on the 200 m (χ2(3) = 20.67, p < .001), 500 m (χ2(3) = 22.42, p < .001), and 800 m (χ2(3) = 22.86, p < .001) radius curves were significantly faster for drivers under the influence of alcohol compared with those given a placebo. There were significant effects of alcohol on the SRR and PP on the 200 m, 500 m, and 800 m radius curves. For all of the curves, the SS, SRR, and PP had a tendency to increase as the BrAC increased. The large PP at a high BrAC, accompanied by the high speed, SS, and SRR, resulted in a high probability of lane exceedance. The use of measures of SS, SRR, and PP aided in the improvement of the accuracy of the intoxication detection for the different types of curves. The most important application is to provide guidance for detecting alcohol-impaired-driving