Comparing rider balance and control of bicycle and e-scooter

Introduction: Although e-scooters have become common in many cities, little is known about how e-scooter riders maintain balance, particularly compared with bicycle riders. We conducted a treadmill-based motion-capture experiment to compare steer and roll motions of bicycle and e-scooter riders. Methods: Twelve adults rode a bicycle and an e-scooter on a treadmill at several speeds, either simply cruising or riding as closely as possible to the centerline. A motion capture system recorded steering- and roll-related angles for the vehicle, rider, and their combination as indicators of balance. These angles were analyzed to test the effects of the vehicle, speed, and riding task on the steering and roll motions. Results: No statistically significant between-vehicle difference was observed for steering magnitude, whereas the main statistically significant cross-vehicle differences were expressed in the roll-related outcomes. Relative to bicycling, e-scootering showed statistically significantly larger rider-to-vehicle roll and, at higher cruising speeds, statistically significantly higher dominant frequencies of the rider-vehicle-combined roll and vehicle frame roll. The rider upper-lower body roll differential was statistically significantly greater in the centerline-tracking task for both vehicles. The combined rider-vehicle roll angle captured these balancing-related changes more consistently than the vehicle-frame-only roll angle, especially for the e-scooter. Conclusions: Bicycle and e-scooter riders move differently to perform the same riding tasks: e-scootering showed larger rider-to-vehicle roll and, at higher cruising speeds, higher dominant frequencies of the rider-vehicle-combined roll and vehicle-frame roll. The rider-vehicle-combined roll angle captured these balance-related differences more consistently than the vehicle-frame-only roll angle. Methodologically, the treadmill-based motion capture setup offers a reproducible approach to characterizing micromobility balancing strategies. Practical Applications: Understanding the different balance requirements between cycling and e-scootering may help explain the difference between bicycle and e-scooter crashes, which in turn could support more effective safety measures such as safer vehicle and infrastructure design.