Influence of Familiarity on the Driving Behavior, Route Risk, and Route Choice of Older Drivers

For older adults, familiarity plays an important role in reducing driving errors, improving wayfinding, and maintaining driving confidence. However, only a few studies have explored the influence of familiarity on driving behavior, route risk, and route choice among older drivers. The vehicles of 29 drivers age 65 and older were instrumented with on-board diagnostic devices for four months to record their routes driven, and risky driving behavior events. For each route driven, trip diaries were used to provide participants with retrospective feedback of their risky driving behaviors, alternate low-risk routes, and record answers to three questions pertaining to: familiarity with the route driven, suggested low-risk route alternative, and reasons for choosing a route. When familiarity responses were regressed on the number of risky driving behavior events, results showed that for every 10% increase in familiarity with driven routes, a 0.07 increase in risky driving behavior incidents per trip was estimated. Results from the generalized mixed effects regression showed that older drivers were less likely to drive a suggested low-risk route when they were more familiar with the alternate routes. Content analysis conducted on the reasons for choosing a familiar route showed that older drivers preferred routes that were direct, had less traffic, and depended on the trip purpose, such as running multiple errands. These results provide important insights on the influence of familiarity on route choice, preferences, and driving behaviors of older drivers and provide opportunities for developing targeted route choice models for navigation systems that can include factors such as familiarity.