Spatial, environmental and social factors affecting active mobility: the case of Barcelona

Abstract

As cities strive for sustainable development, understanding how urban mobility interventions impact environmental health is critical. This study evaluates the effects of a simulated 25% reduction in vehicle traffic on air and noise pollution levels in two dense districts of Barcelona: Sant Marti and Eixample. Using AIMSUN microsimulation and the CNOSSOS-EU noise model, the research quantifies changes in nitrogen dioxide (NO₂), fine particulate matter (PM₂.5), and noise emissions under different traffic scenarios. Results reveal significant improvements in air quality, with reductions of approximately 30% in NO₂ and PM₂.5 concentrations for both locations. However, noise pollution showed only modest decreases of 1–2 dB, insufficient to meaningfully impact urban noise exposure. A specific analysis of the elderly population, focused on trips to pharmacies, healthcare, and community services, demonstrated similar reductions in pollutant exposure (around 31–32% decreases in NO₂ and PM₂.5), highlighting how targeted mode-shift policies can particularly benefit vulnerable groups who are most affected by air pollution. These findings highlight the effectiveness of moderate traffic reductions in meeting upcoming European Union air quality targets and improving public health. Nevertheless, they also underscore the need for complementary noise abatement strategies to address urban soundscapes comprehensively. The study concludes by recommending integrated policies combining traffic reduction, active mobility promotion, and targeted noise mitigation to foster healthier and more sustainable urban environments in Barcelona.