Influence of Horizontal Bike Lane Curve Geometry on Micromobility Users’ Operational Behaviour: A Test Track Study with Bicycles and E-Scooters

Micromobility requires comfortable and safe cycling infrastructure. However, evidence-based geometric design criteria remain limited, particularly regarding the influence of horizontal curve geometry on cyclists and e-scooter riders. This study investigates the influence of horizontal curve geometry in bike lanes on speed and trajectory under controlled experimental conditions. A closed-circuit test track comprising eight horizontal curves with a constant radius of 5 m and deflection angles from 30° to 105° was used. Cyclists and e-scooter riders performed left- and right-turn manoeuvres under free-flow conditions. Operational data were extracted through video-based image analysis and analysed using descriptive, repeatability, and non-parametric inferential methods. Minimum operating speeds generally decreased with increasing deflection angle, with significant differences mainly between lower- and higher-deflection configurations. Male participants exhibited higher mean minimum speeds, although after correction for multiple comparisons, a significant gender difference remained only at 75°. No systematic gender-related differences in lateral positioning were identified. Trajectory behaviour showed direction-dependent differences, while minimum-speed location and longitudinal speed variation differed across experimental configurations. Overall, the findings provide an experimental basis for developing behaviourally informed geometric design criteria for urban micromobility infrastructure.