To examine links between naturalistic (real-world) driving behavior and motor and non-motor disease symptoms in Parkinson's disease (PD).

Cognitive, visual and motor declines in PD affect driving behaviors, which in turn may index disease severity. Studies show PD drivers drive less and self-restrict risk exposure (e.g., reduced driving during nighttime). It remains unclear how PD disease severity impacts driver mobility.

Thirty active, licensed drivers with PD (age = 66.9 ± 6.53, median Hoehn & Yahr II, 21 Male) completed visual, motor, and cognitive assessments, including MDS-Unified Parkinson Disease Rating Scale (UPDRS) for symptom severity. Naturalistic driving was observed for 4 weeks using sensor packages installed in drivers’ own vehicles. Digital driver mobility data quantified distance travelled in different roadway environments (nighttime, high traffic, interstate/residential/commercial roads [20-30, 35-45, ≥ 55 mph]).

3,974 drives (30,428 miles) were captured. PD drivers with worse motor symptoms (UPDRS Part III) drove less on nighttime, high traffic, and interstate roads (ps < .01). Worse motor complications (UPDRS Part IV) reduced interstate (b = -0.148, p < .01) and residential driving (b = -0.101, p < .01). Non-motor symptoms (UPDRS Part I) primarily reduced nighttime (b = -0.146, p = 0.019) but not interstate driving (b = 0.298, p < .001).

This study of real-world driving exposure profiles in PD underscores previous results showing patterns of self- restriction to mitigate risk. Real-world digital driving profiles in PD are related to motor and non-motor symptom severity on standard PD assessments (UPDRS). Findings highlight the need to understand how this multifaced disease maps onto real world behavior, and how digital metrics of real-world behavior may index disease status in PD.