Street Experiments Across EU Cities: An Exploratory Study on Leveraging Data for Urban Mobility Impact Evaluation

European cities are under pressure to be at the forefront of climate neutrality while providing inclusive, safe, and sustainable urban mobility. Street experiments are being adopted to accelerate this transition, yet assessing their impact remains challenging. This study addresses this gap by providing an evidence-based impact assessment of street experiments. The research builds on insights from 20 European cities, including 13 from the EU Cities Mission, regarding expected goals and current evaluation barriers. A preliminary quasi-experimental spatial and temporal approach is proposed and further enriched through the identification of the most relevant mobility domains and indicators addressed by cities. An exploration of data collection technologies is undertaken to meet the cities’ needs, culminating in the design of a portable and easy-to-install laboratory, the Labkit, for in situ and non-intrusive evaluation of public space interventions. The Labkit is tested and validated in an open area with a constant flow of pedestrians, cyclists, e-scooters, and vehicles. The results of this testing process, along with feedback from cities regarding the methodological approach and potential indicators, are analysed. The study concludes with a discussion of the opportunities and limitations of data-driven approaches for urban mobility impact assessment and the proposal of future research directions.