Comparing visual performance and useful field of view of older and younger drivers

Older licensed drivers are involved in more crash deaths than any other age group. A critical issue in reducing these accident numbers is to improve our understanding of the association between the visual performance of these older drivers and their useful field of view (UFOV) when driving. We estimated driver saccadic amplitudes and fixation durations for ten different traffic scenarios using a driving simulator. Six traffic situations presented dangerous or other relevant events to the drivers, with the other four having no dangerous or relevant events. To estimate saccadic amplitudes and fixation durations, eye position data was analyzed during the five seconds before and five seconds after the traffic situations. Results imply that eye movements, fixation durations and number of fixation change as a function of the visual stimuli presented in each traffic situation. The difference in age was found to be significant for number of fixations and fixation time, but not for the total eye movement. Based on these results, we expressed UFOV as a function of saccadic amplitude between fixation points and durations, and estimated the ranges of a sequence UFOVs during the 10-second period for each traffic situation. Our findings suggests that UFOV radius depends on driving scenario, time of event, age-group, driving course, two-factor and three-factor interactions among these variables.