Joshua D. Hoffman

Scrolling and Driving: How an MP3 Player and Its Aftermarket Controller Affect Driving Performance and Visual Behavior

Objective: The aim of this study was to assess how scrolling through playlists on an MP3 player or its aftermarket controller affects driving performance and to examine how drivers adapt device use to driving demands. Background: Drivers use increasingly complex infotainment devices that can undermine driving performance. The goal activation hypothesis suggests that drivers might fail to compensate for these demands, particularly with long tasks and large search set sizes. Method: A total of 50 participants searched for songs in playlists of varying lengths using either an MP3 player or an aftermarket controller while negotiating road segments with traffic and construction in a medium-fidelity driving simulator. Results: Searching through long playlists (580 songs) resulted in poor driving performance and required more long glances (longer than 2 s) to the device compared with other playlist lengths. The aftermarket controller also led to more long glances compared with the MP3 player. Drivers did not adequately adapt their behavior to roadway demand, as evident in their degraded driving performance. No significant performance differences were found between short playlists, the radio-tuning task, and the no-task condition. Conclusion: Selecting songs from long playlists undermined driving performance, and drivers did not sufficiently adapt their use of the device to the roadway demands, consistent with the goal activation hypothesis. The aftermarket controller degraded rather than enhanced performance. Application: Infotainment systems should support drivers in managing distraction. Aftermarket controllers can have the unintended effect of making devices carried into the car less compatible with driving. These results can motivate development of new interfaces as alternatives to scrolling lists.

Reading Text While Driving Understanding Drivers’ Strategic and Tactical Adaptation to Distraction

Objective In this study, we investigated how drivers adapt secondary-task initiation and time-sharing behavior when faced with fluctuating driving demands. Background Reading text while driving is particularly detrimental; however, in real-world driving, drivers actively decide when to perform the task. Method In a test track experiment, participants were free to decide when to read messages while driving along a straight road consisting of an area with increased driving demands (demand zone) followed by an area with low demands. A message was made available shortly before the vehicle entered the demand zone. We manipulated the type of driving demands (baseline, narrow lane, pace clock, combined), message format (no message, paragraph, parsed), and the distance from the demand zone when the message was available (near, far). Results In all conditions, drivers started reading messages (drivers’ first glance to the display) before entering or before leaving the demand zone but tended to wait longer when faced with increased driving demands. While reading messages, drivers looked more or less off road, depending on types of driving demands. Conclusions For task initiation, drivers avoid transitions from low to high demands; however, they are not discouraged when driving demands are already elevated. Drivers adjust time-sharing behavior according to driving demands while performing secondary tasks. Nonetheless, such adjustment may be less effective when total demands are high. Application This study helps us to understand a driver’s role as an active controller in the context of distracted driving and provides insights for developing distraction interventions.

Reading while driving: a study on drivers' strategies of in-vehicle task initiation

In spite of increased public awareness and an ever-growing body of research, driver distraction remains an important safety concern. Reading text while driving may be especially detrimental by imposing both visual interference and extra cognitive demand on drivers. However, in most cases, drivers do not passively respond to such a task, they actively decide when to perform the task. The current study investigated drivers’ strategies with respect to the initiation of text reading when faced with fluctuations in driving demand. Text messages were made available to participants shortly before the vehicle entered an area with increased driving demands (demand zone). Participants were asked to read the message before the end of the trial, but were free to decide when and how to read the messages. We manipulated the type of driving demand (baseline; three levels of high demand—narrow lane, pace clock, and ultimate [narrow + pace clock]), format of text (no message; paragraph; parsed), and the distance from start of message to the demand zone (near; far). The results showed that in most cases drivers started to read the text message before or in the demand zone even though they would have enough time to complete the task after passing the area. Nonetheless, task initiation time (measured from the appearance of the message to the drivers’ first glance to the display) increased when driving was demanding compared to the baseline condition. It suggests that drivers may be sensitive to transitions from low to high demand when initiating secondary tasks, however are not discouraged from such activities when demands are already elevated.