How Do Task Structure and Uncertainty Influence Task-Interleaving Strategies During Distracted Driving?

During distracted driving, people commonly alternate or interleaveattention between driving and another task. One factor that influences taskinterleaving is task structure. Specifically, people tend to switch between tasks atsub-tasks boundaries. Uncertainty about the roadway environment during glancesaway from the road, however, may play a larger role in shaping task interleavingstrategies during distracted driving. The purpose of this study was to examine taskinterleaving strategies when drivers completed a distracting task of various subtasksizes. Participants entered phone numbers, modified zip codes, or digitstrings while performing a lane-keeping task. In general, the time between buttonpresses in the secondary task was significantly greater between sub-tasks thanwithin sub-tasks. However, as sub-tasks became larger drivers switched morefrequently within sub-tasks than between sub-tasks. Additionally, participants’ didnot change their visual sampling strategies as the size of sub-tasks increased.Thus, uncertainty influenced decisions to switch between two interleaved tasks inthe driving environment more than sub-task boundaries