Drivers' visual search in a field situation and in a driving simulator

The aim of the study was to evaluate the validity of using a fixed base driving simulator for in-vehicle visual search studies. A repeated measures experiment was carried out in two conditions: (i) a controlled field situation and (ii) a fixed base driving simulator with computer generated images replicating the field situation. Eye-movements were measured using a NAC Eye Mark Recorder V. The effect of driving situation on eye-movement strategies was evaluated with experience as a between-subjects factor and driving task as a within-subjects factor. The driving tasks evaluated were straight line driving and controlled overtaking using a confederate vehicle. Results revealed that there were no significant differences between conditions in the spatial distribution of eye-fixations on the visual field. However, in the simulator situation more eye-fixations were made overall and inexperienced drivers appeared to alter their visual search strategies to a greater extent. Also, the absence of peripheral vision in this simulator led to significantly higher numbers of fixations to the speedometer. The implications are that fixed base driving simulators are a relatively valid means of studying visual search strategies at a global level.