The effects of age and alcohol intoxication on simulated driving performance, awareness and self-restraint

Abstract

Aims: to investigate whether, compared with middle-aged men (aged 30-50), older men (age ≥ 60) (i) perform more poorly on a driving simulator and (ii) are more sensitive to the effects of ethanol in terms of blood alcohol concentration (BAC) and driving performance, but more aware of their driving difficulties, and therefore exercise better driving judgement. Methods: 14 healthy middle-aged men (mean age 36 years) were compared with 14 healthy older men (mean age 69 years) on an interactive driving simulator, while sober and while legally intoxicated (BAC > 80 mg/dl). Results: older age was associated with poorer driving performance on the simulator. While sober, older men exhibited more improper braking, slower driving, greater speed variability fewer appropriate full stops and more crashes, and spent more time executing left turns (across oncoming traffic); all values ≤ 0.02. BACs ≥ 80 mg/dl were associated with impaired driving, with more inappropriate braking, fewer appropriate full stops and more time executing left turns (all values ≥ 0.02) and trends towards more speed variability, more low speed collisions and more wrong turns (values < 0.1). However, similar ethanol consumption did not produce higher peak BAC or more driving impairments in older drivers. While there were no differences between age groups in terms of awareness of intoxication or driving difficulties, older men were unwilling to drive while legally intoxicated because of fear of physical injury, whereas middle-aged men were more likely to avoid driving when intoxicated due to fear of legal ramifications. Conclusion: while both age and legal intoxication affected driving performance, older men were no more sensitive to ethanol in terms of peak BACs, driving performance or awareness/judgement than middle-aged men.