An Investigating Study on Lateral Riding Position of Cyclists from Curb Based on Road Segment Scope Trajectory Data

Cyclists on urban roads are supposed to ride on bicycle lanes or near the right-side curb. However, lane-out riding is often observed on roads especially when a marking line is present or the lane space is constrained. This paper made a video observation for different bicycle lane designs (fence, marked, and shared), in which the average lateral riding position was concluded with segment scope trajectory data. It finds that, even though different lane width is given, there is a natural riding distance from curb for cyclists to pressure (1.6 m for shared and 2.2 m for separated). Marking line has limited effectiveness in constraining riding position and will conversely cause marking-avoid riding. Providing enough lane width can reduce the likelihood and severity of riding outside the lane. The results may give references to road facility design and help the development of AV systems against mixed traffic and complex road conditions.