School of Psychology

Passenger, Driver Distraction and Motor Vehicle Crashes.

A study to investigate the effects of passengers, age, experience and sex on driver distraction, measured by driving performance.

 Research Description: Previous research into the effects of passengers on driver distraction has found that the presence of passengers contributes to an increased risk of a motor vehicle crashes. This has been found to be particularly evident for younger drivers, as distraction is more likely to be experienced by younger drivers.

Research Summary:
According to the Australian Transportation Safety Bureau, 1601 road fatalities occurred as a result of 1456 motor vehicle accidents in Australia during 2006. Little is understood on how driver’s exposure to distracting activities such as the carriage of passengers impacts on road safety and driving performance (McEvoy et al., 2006).
Research Aims
The research investigated the effects of driver distraction on age, experience and driver sex variables on as measured by reaction times and number of vehicle crashes. A secondary aim of the research was to examine the perceptions of both drivers and passengers regarding the risks involved in several common activities that distract drivers from driving tasks and the safe operation of a vehicle.
What was done
Using a combination of Murdoch University student participants and participants from a convenient sample available to the investigators, 55 individuals (22 male and 33 female) were required to complete three 15 minute simulated driving scenarios in which they drove with a speaking passenger, a silent passenger and alone. During the driving simulation, participants were required to navigate a 10 kilometre roadway and brake as quickly as possible to numerous traffic hazards that would suddenly appear on the roadway ahead. A further 187 participants completed two questionnaires, one from a passengers perspective, and the other from a drivers perspective, in which they were questioned on their beliefs regarding a number of common driving activities that distract drivers.
What was found
Driving simulator data showed that drivers travelling with a speaking passenger produced substantially slower reaction times to road hazards, and were involved in a greater number of vehicle crashes when compared to drivers that travelled alone. Interestingly, drivers travelling with a silent passenger also experienced slower reaction times to hazards and were involved in a greater number of crashes when compared with drivers carrying no passengers. No age, sex or driving experience differences were found, suggesting that driver gender, age, and length of driving experience do not influence the likelihood of drivers becoming distracted by passengers. Finally, questionnaire results found that participants do not believe that passengers are particularly distracting or detrimental to driving performance, despite reporting that their most recent crashes involved some form of driver distraction. Participants reported mobile phones as being the most dangerous to driving performance. This highlights the result of educational campaigns and legislation in place to curb the use of mobile phones while driving.
Concluding Remarks
It was concluded that despite common beliefs regarding the non-distracting effects of passengers and no subsequent detriment to driving performance, simulation data revealed that drivers do become distracted when passengers are present in the vehicle, and driving performance is negatively affected. Further research into the underlying behavioural mechanisms that occur between drivers and passengers is required to gain a greater understanding of the relationship between passenger and driver. It was concluded that greater education for road users regarding the distracting effects of passengers and the potential risks involved in engaging in distracting activities is required to help alleviate the growing road toll.