LAUSR

Abstract Driving under the influence of alcohol impairs the driving performance and increases the crash risks worldwide. The present study investigated the effect of different Blood Alcohol Concentrations (BAC) on the reaction time of Indian drivers of two age groups (Young: less than 25 years; Mature: 25 years and above) through a driving simulator experiment. Reaction times were measured for the two hazardous events: (1) pedestrian crossing event and (2) road crossing event by parked vehicles. Seventy nine licensed drivers drove on the driving simulator under the influence of four BAC levels (0.00%, 0.03%, 0.05% and 0.08%). To analyse the reaction times, two Weibull AFT (Accelerated Failure Time) models with gamma frailty were developed for both the events separately by incorporating the different alcohol conditions and driver characteristics (such as driver’s age, driving experience and frequent consumption of alcohol) as the explanatory variables. It was observed that the BAC levels of 0.03%, 0.05% and 0.08% resulted in 36%, 53% and 94% increment in the reaction times of the drivers for the pedestrian crossing event and 64%, 78% and 116% increment in the reaction times for road crossing event by the parked vehicles respectively. A year increase in the driving experience resulted in 2% reduction in the reaction times, and mature drivers responded 15% faster than the young drivers. Interestingly, frequent drinkers showed 11% quicker response than the drivers who drink rarely. Overall, the results showed that the stimulus-response behaviour of the drivers was impaired in all the intoxicated states. The research findings may assist the countermeasure studies and policy-making against alcohol-impaired driving.