How to create a sustainable growth in bicycle traffic? The case of Paris

In recent years, cycling has received notable investments in response to the urge to decarbonize the transportation sector, leading to an increase in its modal share in many territories. The present article presents a longitudinal study that evaluates the impact of various public policies on bicycle growth in Paris over the period 2018–2023. Variables of interest can be classified according to five themes: targeted cycling policies, restrictions imposed on motorized vehicles, disruptions on other modes of transport, livability policies, and economic conditions. The methodology is based on dependence-aware sensitivity analysis techniques to assess the separate contributions of each of these variables on bicycle traffic, aggregated at the city scale, and extracted from ground counter data. In order to be exhaustive, variations due to weather and calendar dynamics are also controlled for. Results indicate that local authorities should primarily focus on the development of bicycle infrastructure, including bicycle lanes, parking slots, and effective bicycle-sharing systems. While these measures are instrumental, sustainable growth relies on the implementation of a diverse range of policies. Bicycle usage can be further expanded by making it more attractive, specifically through the creation of pedestrian zones and green spaces, or the promotion of e-bikes. Additionally, cycling tends to increase as car usage becomes more difficult, although this finding calls for equity considerations.