How Intensity-to-Capacity (IC) Ratios on Cycleways Impact Cyclists' Perceived Safety, Flow, and Comfort

As cities assess old and new cycleways to accommodate more cyclists, understanding the capacity limits of these paths has become crucial to sustainable growth. Cyclists’ safety, comfort, and flow determine these capacity limits, and traditionally, researchers have assessed them through on-site observations and surveys. This study introduces an alternative method, utilizing an off-site cycling simulator to investigate how increasing intensity-to-capacity (IC) ratios influence perceived safety, comfort, and flow on a high-capacity Antwerp cycleway. The key metric, IC ratios, assesses traffic volume, i.e., intensity, in relation to the estimated road capacity. Researchers tested three increased IC ratios compared to the current IC ratio of 0.269: 0.33 (mild: +22.68%), 0.51 (moderate: +89.59%), and 0.69 (high: +156.51%). Fourteen participants provided post-session feedback using Likert-scale questionnaires (1-5 scale). The results indicated that as the IC ratio increased, perceived safety and comfort declined, while flow interruptions became more frequent. Although the study did not identify a critical threshold where these factors significantly deterred cyclists, it is possible that the highest IC ratio tested was not sufficient to reveal such a point, though the methodology appears capable of detecting it at higher values. Notably, participant responses aligned with expectations, suggesting the simulator’s potential as a tool for analyzing IC ratios in future research. This methodology offers urban planners a controlled, off-site approach that provides flexibility and efficiency compared to traditional in situ studies, which lack controllability. Lastly, this methodology provides a way to analyze potential future high-intensity scenarios.