This study addressed the following questions: 1) Do drivers have strong expectancies or stereotypes for locations of controls and displays (defined as components that the driver must reach and manipulate to use)?; 2) Do older drivers have different expectancies or stereotypes for these locations than younger drivers?; 3) Do expectancies affect search and location time?; and 4) Are older drivers even slower compared to younger drivers when searching for controls when the control is not in the expected location? The authors found that drivers do have strong location expectations for many controls, and that their expectations mirror the most common locations actually found in vehicles. They also found that some location expectancies have changed over time, and for some controls which have changed location there is "expectancy lag" in location expectancies. Older drivers had essentially the same location expectancies as the younger participants. The data indicate that location expectancies do affect location times for people when they drive an unfamiliar vehicle. In two instances where controls were far from the expected location, no drivers were able to find them during the experimental period. Although there were no substantial differences in the location expectancies of older and younger participants, older drivers were generally slower at locating controls and displays in unfamiliar passenger cars. Closer examination revealed that they were significantly slower in locating about 30% of the controls. The factors which make older drivers significantly slower than younger drivers at locating some controls but not others remains to be determined. Average times to locate controls in the three test cars were significantly and substantially different. This indicates that different display and control layouts impose different attentional "loads" on drivers as they search for a control or display. As the driving task itself imposes a substantial cognitive load on drivers, it is important to minimize the load imposed by tasks such as identifying and locating controls and displays. This is particularly important for older drivers whose attentional resources are diminished. It was concluded that as the driving population ages and the driving task itself becomes more complex, we need to reconsider the issue of standardization of control and display location. (A)
Samenvatting