Evaluation of Solar Adaptability in Transit Station Areas: A Comparative Case Study of Tokyo and Hong Kong

Due to climatic differences between cities, there is a complex relationship between urban form and sunlight comfort. In the compactly developed transit station areas, the higher development intensity further limits the space for urban form adjustment, making it difficult to maintain ideal sunlight conditions in all public spaces. This study aims to provide a method for assessing the solar adaptability of public spaces around rail transit stations. By constructing a betweenness-solar performance (B-S) model, the appropriateness of spatial form in station areas is assessed based on the balance between predicted pedestrian flows and sunlight conditions in urban public spaces. The article selected three transit stations each in Tokyo and Hong Kong as case studies. The results indicate that the B-S model is helpful in identifying specific locations within the station areas that have issues. Preliminary strategies have been summarized for spatial form optimization, including shadow control under different climates, open space design methods, and increasing the connectivity of street networks. The application of these strategies will help improve sunlight conditions in the core areas of the stations and minimize the loss of overall development intensity in the station areas.