Effects of different blood alcohol concentrations and post-alcohol impairment on driving behavior and task performance.
OBJECTIVE
A study using simulator methodology was conducted to investigate the effects of (1) different blood alcohol concentrations (BAC) of 0, 0.05, 0.08, and 0.10 percent and (2) post-alcohol impairment (where BAC approximately 0%) on driving behavior and subsidiary cognitive task performance.


METHODS
Two driving sessions were investigated, that is, drunk driving and post-alcohol driving, with each requiring approximately 20 min of driving. In addition to driving safely, participants were instructed to perform the critical flicker fusion (CFF) test and completed the NASA-TLX mental workload questionnaire. Eight licensed drivers (6 males, 2 females) participated in this 2 (road complexities) x 2 (simulated driving sessions) x 4 (levels of BAC) within-subjects experiment.


RESULTS
The study revealed that higher BAC levels were associated with lower performing driving behavior. The driver's mental workload reached the highest values in the post-alcohol session. In terms of tasks involving divided attention, the traffic sign distance estimation showed significant deterioration with increased BAC levels.


CONCLUSIONS
The relationship between drunk-driving behavior and alcohol dosage was supported in this study. Noticeably, no significant difference was found between drunk driving and post-alcohol driving, indicating that even in the post-alcohol situation, the impairment still remained significant enough to jeopardize traffic safety as much as it does in the case of drunk driving. In real-life situations, adopting a rest-time strategy to avoid post-alcohol impairment effects may not be the most appropriate solution by drivers; rather, drivers should be given some tests to verify the probability of post-alcohol effects on driving.
Liu
Yung-Ching
YC
Department of Industrial Engineering and Management, National Yunlin University of Science and Technology, Douliu, Taiwan. liuyc@yuntech.edu.tw
Ho
Chin Heng
CH
D000328:Adult; D000435:Alcoholic Intoxication / Q000097:blood / Q000523:psychology*; D001334:Automobile Driving / Q000523:psychology*; D003071:Cognition; D003198:Computer Simulation; D000431:Ethanol / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D013647:Task Performance and Analysis; D013997:Time Factors; D055815:Young Adult
D000431:Ethanol