How do you assess the distraction of in-vehicle information systems? : a comparison of occlusion, lane change task and mediumfidelity driving simulator methods.

There are several simplistic, low-cost methods for evaluating the distraction of in-vehicle information systems (IVIS), intended primarily for use in the formative design process. This study compared two standardised low-cost evaluation methods, Occlusion and Lane Change Task (LCT), with a medium-fidelity driving simulation. Participants carried out tasks using an in-vehicle information system under three conditions: Using the occlusion protocol; LCT; and while driving on a motorway in the simulator. Findings provided strong evidence that the occlusion technique is a stronger candidate than the LCT for evaluating driving distraction due to IVIS. Measures from the occlusion technique (Total Shutter Open Time —TSOT; and Task Time with full vision) were found to correlate highly with the majority of the driving simulator measures (total glance time, mean glance time, driving task time, standard deviation of headway and standard deviation of lane position). Importantly, TSOT was found to successfully predict the number of long off-road glances (greater than two seconds), a critical safety-related measure. In contrast, the key LCT measure of mean deviation provided little predictive ability in considering varying tasks and systems. (Author/publisher)