Does a cautious driving style reduce the crash risk of older drivers? An analysis using a novel driving style recognition method

Abstract

Older drivers who are aware of their declining functions tend to adopt a cautious driving style to compensate for their declining driving abilities. However, whether cautious older drivers are associated with a reduced crash risk has not been well studied. In this study, we examined the association between older drivers’ cautious driving style and crash risk using a novel driving style recognition method. We proposed a driving style recognition method that does not require predefined thresholds and applied it to the driving data of 71 drivers comprising 59 drivers aged 65 years or older (mean age 72.4; 67.8 % male) and 12 drivers aged 51–64 years (mean age 58.3; 66.7 % male). Drivers were classified into cautious and relatively aggressive groups based on the classification results of their speed, acceleration, and braking styles. The results showed that cautious drivers were characterized by older age, poorer Trail Making Test Part B performance, less frequent night driving, and lower driving exposure, indicating that older drivers may adopt multiple compensatory strategies. Although the crash involvement rate of cautious older drivers was approximately half that of relatively aggressive drivers, the difference was not statistically significant. Furthermore, this difference was expected to decrease when driving exposure was considered. Older drivers who adopted a cautious driving style but were involved in traffic crashes had poorer visual acuity and contrast sensitivity. The results of this study indicate that a cautious driving style alone may not be sufficient to compensate for older drivers’ declining functions, particularly the loss of two visual functions observed in the present study.