Walking smart in the heat: A dynamic shade-oriented pathfinding approach to enhance pedestrian comfort in arid cities

Abstract

In recent decades, rapid population growth in Middle Eastern cities has led to increased motorization and rising carbon emissions, particularly in car-oriented, high-density urban environments like Dubai. In response, cities are expanding their public transportation systems and promoting walking and cycling. However, scorching temperatures make the choice of active mobility challenging. This study presents a methodology to evaluate pedestrian walking environments by comparing the alignment between the shortest and optimal shadiest paths around metro stations in Dubai. Unlike existing models that apply a constant shade reward, we develop an optimal shadiest path method that assigns dynamic rewards to buildings, trees, and indoor shade, which better reflects real-world conditions. Additionally, we highlight the often-overlooked role of indoor paths in enhancing pedestrian thermal comfort, particularly in arid cities. To quantify both the shortcut effect and the shade improvement of indoor paths, we introduce the Indoor Contribution Index (ICI), a metric that assesses the role of indoor routes in improving pedestrian thermal comfort and walking efficiency. The results reveal that, on average, the optimal shadiest path is 1.3% longer than the shortest path, with an 8.9% increase in building shade and an 8.8% decrease in sun exposure compared to the shortest path. Additionally, both temporal factors and spatial characteristics significantly influence the utility of indoor routes in enhancing thermal walking comfort. Our findings highlight the need for further research into smart pathfinding algorithms that can guide pedestrians through hot environments, as well as the integration of indoor networks into urban mobility systems, particularly in Middle Eastern cities and other regions with harsh outdoor conditions.