Effects of variations in driving task attentional demand on in-car navigation system usage

Abstract

This research was conducted to assess whether drivers, while navigating using an Etak automobile moving-map navigation system, could adapt when necessary to situations where higher levels of visual attentional demand associated with driving occur. Two studies were performed to answer this question. The first dealt with changes in anticipated attentional demand. These changes were of the type that the driver could observe ahead of time. The attentional demand levels (low, medium, and high) were based on subjective and objective ratings of roadway segments which the drivers navigated. The second study assessed changes in unanticipated visual attentional demand. The demand levels were based on the type of interaction or monitoring required of other vehicles by drivers. The levels were light traffic, heavy traffic, and incident. Twenty-four subjects participated in this research. Twelve males and 12 females were divided evenly into three age groups {18 to 30, 31 to 44, and 45 to 65). They were unfamiliar with the destinations to which they drove. Data were collected on eye glance duration and glance patterns. The overall results for both studies showed that drivers do in fact adapt to some degree to increases in attentional demand. Generally speaking, as attentional demand levels increased, drivers adapted by increasing the proportion of visual time spent viewing the forward roadway and decreasing the proportion of visual time spent viewing the Etak.