Sustainable active transportation infrastructure for urban heat adaptation and mitigation: A systematic literature review

Cities worldwide are facing increasing heat stress that threatens public health, livability, and the usability of active transportation networks. Despite growing efforts to expand active mobility, microclimatic conditions are often insufficiently integrated into transport planning and design. This study synthesizes global evidence on how urban form and active transportation infrastructure influence heat exposure for pedestrians and cyclists through a dual-method review approach. A bibliometric analysis of 1661 publications maps the evolution and fragmentation of research at the intersection of urban climate and active mobility, while a PRISMA-based systematic review of 178 empirical studies applies a structured qualitative coding framework to assess infrastructure typologies, urban morphological parameters, thermal metrics, and cooling strategies across climate zones and spatial scales. Cooling effects are reported either as reductions in air temperature or as changes in thermal comfort indices such as Physiological Equivalent Temperature (PET) and the Universal Thermal Climate Index (UTCI). Across the reviewed literature, climate-sensitive design elements, including vegetation, shading, reflective materials, water features, and optimized street geometry, are associated with reductions in thermal exposure of up to 10 °C. Pedestrian-only streets, sidewalks, and greenways typically exhibit reductions of 2–3 °C, while reported cooling effects for cycling infrastructure range from 0 to 9 °C for bike lanes and 1–1.5 °C for cycle superhighways. Key morphological drivers include sky view factor (SVF), height-to-width (H/W) ratios, street orientation, density, and surface materials. Case studies demonstrate co-benefits for walkability, social interaction, and air quality. To support practical application, we introduce an evidence-based framework linking climate zones to optimal cooling strategies, expected thermal outcomes, and behavioral benefits.