Examination of naturalistic driving practices in drivers with Parkinson's disease compared to age and gender-matched controls.

A few studies suggest that drivers with Parkinson's disease (PD) may self-regulate or modify their driving behavior more than drivers without neurological disorders; however findings are limited to self-report. The purpose of this study was to objectively examine whether drivers with PD show more restrictive driving practices (exposure and patterns). Electronic devices were installed in the vehicles of 27 drivers with PD (71.6±6.6; 78% men) and 20 matched controls (70.6±7.9; 80% men) for two weeks and driving data were matched with aerial maps, weather and daylight archives and trip logs to examine driving context. Compared to controls, the PD group drove significantly less overall (number of trips, kilometres, duration), and proportionately less at night and on days with bad weather suggesting more restricted driving practices, congruent with lower ratings of driving comfort and abilities. However, they may not necessarily drive more cautiously or safely as they drove significantly faster (and over the speed limit) on highways and freeways and 19% reported driving problems over the two weeks. These preliminary findings need to be replicated and longitudinal studies using objective indicators are needed to examine changes in driving practices, as well as crash outcomes, as disease severity progresses.