Characteristics of low and high mileage drivers: Findings from the Ozcandrive older driver cohort study
Submission Date: November 15, 2018 Journal
Suggested Citation: Hua, P., Charlton, J.L., Koppel, S., Griffiths, D., St. Louis, R.M., Di Stefano, M., Darzins, P., Odell, M., Porter, M.M., Myers, A., & Marshall, S. (2018). Characteristics of low and high mileage drivers: Findings from the Ozcandrive older driver cohort study. Journal of the Australasian College of Road Safety, 29(4), 53-62.
This study used real-world driving data from the Ozcandrive older driver cohort study to examine the relationship between annual mileage driven and a range of demographic and functional factors, self-reported driving comfort, real-world driving patterns and self-reported crashes and citations. Driving data for a subset of Australian participants of the Candrive/ Ozcandrive study (n = 183), aged 75-94 years were included in the analysis. Participants’ real-world annual mileage distances were recorded through an in-car recording device (ICRD) installed in participants’ own vehicles. Participants’ annual mileage distances were grouped into three categories (low: ≤ 5,000 km, middle: > 5,000 – < 13,000 km, and high: ≥ 13,000 km). Preliminary results showed females were more likely to be in the low mileage group compared to male drivers. Additionally, the low mileage group drove significantly more trips 5 km or less compared to the middle and high mileage groups, while the high mileage group drove the greatest percentage of trips beyond 20 km compared to the low and middle mileage groups. On average, the low mileage group reported the lowest total scores on the Driving Comfort Scale compared to the high mileage group which reported the highest total score. However, there were no significant group differences on any tests of cognitive/ functional ability or crash and citation rates. Findings suggest that older adults who drive lower annual mileages may engage in some driving practices that are suggestive of self-regulation. However, a larger-scale study using official crash data is needed to establish whether the low mileage bias is pertinent to older drivers.