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Driving exposure and distraction: A comparison of three in-vehicle tasks

Author(s): Eng, Walker, Trick

Poster Presentation:

2D-Eng

Abstract:

Background:

Distracted driving continues to be a serious threat to safety on the roads. Distracted driving occurs when drivers carry out secondary tasks while driving, producing interference, which is to say that dual task performance (driving while carrying out the secondary task) is worse than single task (driving alone). However, the amount of interference may vary with the secondary task and the extent to which the driver takes on compensatory measures such as compensatory slowing. Moreover, even among licensed drivers the effect of secondary tasks may vary depending on their specific level of driving exposure, with those with low exposure less aware of the extent to which their performance deteriorates while carrying out secondary tasks as measured by self-rated driving performance. Consequently, for a driver with limited driving exposure, even tasks that are currently legal may pose a threat. In this study we focused on young adults at the intermediate level of training (Ontario’s G2), and compared the impact of three in-vehicle tasks: hands-free cell phone conversation, using a touch screen to make music choice, and texting.

Aims:

Overall, our study had three aims.

1. To assess both the driving exposure and frequency with which a sample of young adults drove while having a hands-free cell phone conversation, using a touch screen Mp3 player, and texting.

2. To measure the relative amount of dual-task interference produced by driving while having a hands-free conversation, using a touch screen Mp3 player choose music, and texting, making the comparison in terms of both objectively measured and self-perceived driving performance.

3. To investigate if driving exposure has an effect on the amount of dual-task interference both as measured objectively in terms of driving performance and compensatory slowing and subjectively, in terms of self-rated driving performance.

Methods:

40 young adult drivers with a G2 or better license were surveyed about their driving history and their experience with driving while using cell phones, texting, and touch screen MP3 players. Their driving performance was then assessed using a high fidelity driving simulator. For each driver, single task (driving alone) performance was compared to dual-task performance while carrying out a hands-free cell phone conversation, typing in a music selection on a touch screen Mp3 player, and or texting. We compared objective (simulator-measured) indices of driving performance with self-perceived performance, as measured by self-ratings of driving performance, distraction and difficulty focusing.

Results:

Our results indicated that a number of the young drivers admitted to carrying out all of the three of the secondary tasks while driving, though the frequency varied with the task. We also found that the secondary tasks produced varying amounts of interference as reflected in objective and subjective measures of driving performance, though driving exposure predicted the amount of interference.

Discussion:

Although we found a relationship between dual-task interference and driving exposure, this study was limited in that sample was small and the performance was measured in a driving simulator.

Conclusions:

Overall, we found that distracted driving reduces driving performance with drivers with low driving exposure particularly at risk.