Visual Demand of Driving and the Execution of Display-Intensive in-Vehicle Tasks

Abstract

To gain insight as to when telematics can be distracting, 16 participants drove a simulator on roads with long curves of several different radii. Participants read electronic maps displayed in the center console while both parked and driving. In separate trials, the visual demand/workload of the same straight and curved sections was measured using the visual occlusion technique. Visual demand was correlated with inverse curve radius.As visual demand increased, driving performance declined. Participants made shorter glances at the display, made more of them, but waited longer between glances. Overall, task completion time increased when the task was performed while driving (versus while parked), except for short duration tasks (a single glance or under 3 seconds timed while parked), where task time decreased. While driving, task completion times were relatively unaffected by the driving workload.

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

“…Second, whereas the selfpaced occlusion paradigm allowed visual sampling strategies to be measured, it is not a suitable substitute for eye tracking. The occlusion method, however, is commonly used to measure and estimate visual demand (e.g., Baumann, Keinath, Krems, & Bengler, 2004) and the average occlusion period durations in this study were similar to glance durations observed in previous research (Tsimhoni & Green, 2001). …”

“…The average duration of participants' first three occlusion periods was not significantly different across number entry stimuli. On average, participants only occluded the roadway between 1 and 1.2 seconds, durations that have been found in previous visual sampling research (Tsimhoni & Green, 2001). This suggests that participants were using a similar visual sampling strategy for each number entry stimulus regardless of sub-task size.…”

Do Redundant Head-Up and Head-Down Display Configurations Cause Distractions?

“…According to Tsimhoni and Green (2001), the addition of a secondary task while driving significantly impairs driving performance, which could not be confirmed in this study. Probably due to the simplicity of the secondary task used which was not sufficient to cause extra workload to yield any differences in lane keeping or stress.…”

“…Automobiles are becoming more and more technologically complex (Baber & Wankling, 1992;Noy, 1997) with more and more built-in driver information systems (Tsimhoni & Green, 2001). This also increases the amount, and range, of information presented to the driver, which leads to the use of dynamic displays showing many types of information in one place (Baber & Wankling, 1992).…”

“…Luoma & Rämä (2002) even claim that an invehicle information system should only provide information when it's really needed. Having attention on something other than driving, a secondary task, increases the in-vehicle glance durations and is associated with decreased driving performance and increased crash risk (Horrey & Wickens, 2007;Tsimhoni & Green, 2001). Horrey, Wickens, & Consalus (2005) and Wittman et al (2006) declare that if information is acquired from a display located close to the road view, the driving performance is less degraded than for a distant display.…”