Alcohol and Alcohol Combined with Texting: Evaluation of Driving Impairment Effects in a Closed-Course Section

Abstract

Objective

Examine the driving impairment effects of alcohol alone and of alcohol combined with texting.

Methods

Fifteen drivers (nine male, six female; mean age: 31.1 ± 6.9 years, range: 23 to 43 years) with similar drinking habit (i.e., social drinkers) completed a lap in a closed-course section in six different situations: (I) sober; (II) sober and while texting; (III) 30 minutes after ingesting a moderate dose of ethanol (0.50 g/kg); (IV) 30 minutes after drinking and while texting; (V) 60 minutes after drinking, (VI) 60 minutes after drinking and while texting. Driving performance was analyzed by means of maximum and mean speed, braking time and braking distance; and ability to control the car (i.e., evaluating if the drivers hit a traffic cone or exceeded the boundaries of the course). P values of < 0.05 were considered significant.

Results

Pre and post-alcohol consumption results show a significant increase concerning the drivers’ mean and maximum speed after drinking (p < 3.2x10⁻⁸). However, neither alcohol nor texting had significant effects on braking parameters (p > 0.05). Traffic cones were knocked down only in texting experiments. In addition, when using the cell phone drivers tended to reduce the speed, and to accelerate abruptly right after they finish texting.

Conclusion

Our findings strengthen the hypothesis that even moderate alcohol doses may significantly impair the driving performance. Additionally, alcohol and texting have complementary effects on driving impairment, and their combination represents a significant risk factor for crashes.

Keywords:

• Alcohol
• driving
• cell phone
• speed
• risky driving
• crashes

Acknowledgements

The authors would like to thank Dr. Cynthia Maria de Campos Prado Manso for reviewing the English language, Autoescola Moré for lending the car used in the experiments and the São Paulo State Highway Police for their support during the traffic experiments.

Declaration of interest

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (funding number: Pro-Forense 25/2014).