Comparison of older and middle-aged drivers’ driving performance in a naturalistic setting

•Driving route complexity can be quantified using several environmental indicators.•Driving errors have different risk levels based on error type and route complexity.•Older adults drive on less complex routes than middle-aged drivers in daily living.•Overall driving error rates are low in both age groups; most errors are low-risk.•Middle-aged drivers made more errors and/or drove in more complex environments. There is a concern in the public domain about driving safety among older drivers due the increase in age-associated medical conditions. It is not known how these medical changes impact driving performance and choice of driving environment. This study aimed to compare older drivers’ (≥74 years) driving performance in a naturalistic setting to middle-aged drivers (35–64 years) on their chosen driving environment, and number, type and severity of errors. The effect of sex and perceived driving ability was also examined. Drivers’ performance was studied using the electronic Driving Observation Schedule [eDOS]), a naturalistic observation approach. Fifty-three older (mean age = 80.6 years, 72% male) and 60 middle-aged (mean age = 50.0 years, 50% male) healthy drivers were recruited. Both groups made few driving errors that were mostly low-risk. Driving performance of older adults differed from middle-aged drivers; they drove on simpler routes (fewer intersections and lane changes) and made fewer errors. Findings are likely indicative of older drivers’ use of adaptive strategies to maintain safe driving.