Visibility issues that influence older adults' line of sight during automobile driving

The population of older adults and, consequently, older adult drivers will continually rise over the next several decades. Drivers obtain a great deal of the information critical to safe driving visually from the outside of their vehicles. It was the intent of this study to explore how visual information or lack of information impacts active older adult drivers.;The second study used the information from the first study to develop a questionnaire which was subsequently completed by 184 young and older drivers. Results confirmed that older driver's visual attention location was focused on the front region of the vehicle. Mirrors were preferred for checking traffic versus head and shoulder turning. Height was confirmed to decrease with age at an average change of one centimeter per decade for both males and females from age 30 onward. Older drivers self-limited driving to comfortable and safe circumstances. Driving confidence on roadways and at intersections was lower and visibility issues were related to both driving behavior and driving confidence.;The third study used a simulation program called JACK(TM) to investigate several vision-related driving scenarios shown in the first two studies to be important to older drivers. Results revealed that visibility can be greatly enhanced if seats were adjusted for visibility, pillars and headrests were transparent and mirrors were designed for greater visibility. A reduction in sitting height normally seen with aging was shown to have both positive and negative effects on line of sight. The virtual compact car had the worst visibility, followed by the sedan and sport utility vehicles.;This research demonstrated that visibility is an important concern for the older adult driver. Simulations showed that visibility could be vastly improved by engineering out visual obstructions. Practical driver education is recommended for various situations related to visibility, but most importantly regarding blind spot recognition and visual attention location.;Results from the first qualitative study revealed that visibility is impeded by vehicle design. Vehicle blind spot recognition was variable with some older adults recognizing that they needed to turn and look over both shoulders and others not acknowledging that there was a blind spot. Visual attention location was primarily focused on the front region of the vehicle. Older adults reported varying degrees of driver confidence over various driving situations.;Keywords: Driver education, visibility attention location, blind spot, intersection, virtual simulation.