Shaded Walking Path Planning Tool: Utilising Open Data to Develop Walking Solutions for Urban Heat Islands: A case study of Taichung City, Taiwan.

Urban Heat Island (UHI) effects and rising temperatures challenge the promotion of walkable cities by creating uncomfortable outdoor walking conditions. This study develops a computational tool to enhance pedestrian route planning, integrating solar radiation analysis and sidewalk quality assessments to identify optimal walking paths. Using Taichung City, Taiwan, as a case study, the tool leverages public open data—building footprints, street trees and sidewalks—combined with Grasshopper plug-ins and OpenStreetMap road networks for weighted shortest path computations. Shadow mapping, direct sunlight hours, and solar radiation are analysed with Ladybug Tools, and pedestrian paths are evaluated for shade coverage, sidewalk completeness, and thermal comfort. Results from four types of routes planned by the tool revealed significant improvements in pedestrian comfort through optimized paths and accessible walking environments. This study built a Grasshopper-based toolset that enables dynamic parameter adjustments, offering real-time insights into routing decisions. This approach supports sustainable urban mobility, promoting walkable city lifestyles and contributing to climate-resilient by utilising this tool to avoid heat with limited resources.