When cyclists are overtaken at close distances by motorized vehicles, the narrow space increases the impact of aerodynamic forces, which can destabilize cyclists or lead to accidents (Gromke & Ruck, 2021). Beyond the objective risks, such situations can be stressful or even perceived as “very scary”, even without a collision (Aldred, 2016). The aim of this research is to investigate how overtaking distance affects cyclists' subjective safety, comparing real traffic and simulated conditions.

For this, two complementary studies were conducted. First, in a semi-naturalistic field study, an instrumented bicycle equipped with OpenBikeSensor technology (OpenBikeSensor e.V., 2023) was used to measure overtaking distances during cycling in urban traffic. Cyclists (N = 38) rated their mental comfort immediately after being overtaken by motor vehicles. Second, in an experimental study in a bicycle simulator, overtaking distances were systematically varied between 1.0 and 2.0 m, with participants (N = 50) assessing their perceived safety.
Results show larger overtaking distances significantly enhance cyclists' mental comfort and perceived safety, particularly beyond 1.5 m. They also confirm the validity of the bike simulator as a tool for assessing subjective experience in overtaking scenarios, with participants' responses closely mirroring those observed in real-world traffic.

References

Aldred, R. (2016). Cycling near misses: Their frequency, impact, and prevention. Transportation Research Part A: Policy and Practice, 90, 69–83. https://doi.org/10.1016/j.tra.2016.04.016

Gromke, C., & Ruck, B. (2021). Passenger car-induced lateral aerodynamic loads on cyclists during overtaking. Journal of Wind Engineering and Industrial Aerodynamics, 209. https://doi.org/10.1016/j.jweia.2020.104489

OpenBikeSensor e.V. (2023). OpenBikeSensor. https://www.openbikesensor.org/