Quantifying The Vision Changes That Affect Senior Drivers
April 4, 2011
According to a recent study conducted at Ben Gurion University of the Negev in Israel and published in the online edition of Accident Analysis and Prevention, because of a limited field of view elderly drivers are only half as likely to be able to see pedestrians on the sidewalk and, researchers say, they make up for it in part by driving more slowly.
Though individual skill levels vary widely from person to person, the common perception is that a variety of changes that occur with aging affect driving ability. Ben Gurion University has a Human Factors Safety Lab, which features a 2008 Cadillac sedan and sophisticated simulation technology. The multi-disciplinary lab recently developed one of the world’s only pedestrian simulation labs to conduct research on how pedestrians perceive and react to drivers. For this study, the researchers compared reaction times and perception of pedestrians as hazards between experienced elderly and non-elderly drivers. They used two evaluation methods: driving in a traffic simulator while watching video of traffic scenes and identifying hazardous situations by pressing a button. Video observation method results showed that elderly drivers took longer to respond to pedestrian hazards. Approximately half of the pedestrian-related events presented in the videos were difficult for elderly drivers to perceive when compared with the non-elderly drivers.
The simulator drive test also revealed that the elderly performed “braking actions” half as often as the non-elderly group in response to pedestrians on sidewalks and shoulders. However, the elderly drivers attempted to cope with hazards by reducing their driving speed by almost 20 percent, providing them more time to process the potential hazards and dangers even if they couldn’t detect them.
“These findings strengthen the notion that elderly drivers, shown to have a narrower useful field of view, may also be limited in their ability to detect hazards, particularly when outside the center of their view,” explains Dr. Tal Oron-Gilad, a researcher in BGU's Department of Industrial Engineering and Management. She recommends that while more research is needed, “authorities should be aware of these limitations and increase elderly drivers’ awareness of pedestrians by posting traffic signs or dedicated lane marks that inform them of potential upcoming hazards.” Other BGU researchers in the study included Shani Bromberg, Adi Ronen, Avinoam Borowsky and Yisrael Parmet. The study was supported in part by a scholarship from the Ran Naor Foundation.