A cognitive constraint model of the effects of portable music-player use on driver performance
We describe an approach to modeling strategic variations in how people might select media content from an Apple iPod portable music player while driving. An experiment was conducted to determine the time required to select a target from a list using the scroll wheel on the iPod. It was found that a linear model accurately predicted the time to scroll through a list to a target. This model was then used in conjunction with a previously reported steering control model to derive a priori predictions for dual-task performance over the entire range of possible multitasking strategies. From this set of strategies, we then focused on identifying the fastest and the safest strategies for completing both a simple selection task and also a more complex selection task. It was found that the model predictions bracketed the observed human data from a recent study that investigated the effects of using an iPod while driving. Moreover, the analysis suggests that in order to compensate for the inherent risks of using devices that demand longer interaction episodes to complete a task, people might adjust their multitasking strategy by giving more time up to steering control while completing the secondary task.