Age-Friendly Environment Design of High-Speed Railway Stations from a Healthy Ageing Perspective: A Case Implementation in Nanjing, China

China stands out as one of the countries with the largest and fastest-growing elderly populations. Elderly requirements for the quality of high-speed railway stations environment are increasing. The relationship between the built environment of high-speed railway stations and elderly health has become an urgent problem to be solved. The challenge necessitates a systematic approach to age-friendly design. Based on the practical experience of the authors in an age-friendly design of an indoor environment at Nanjing South Railway Station, questionnaire surveys and user interviews were employed to profile four types of typical elderly passengers. Data collection methods were used to create behavior maps. (1) This study identifies the age-friendly needs of elderly passengers, pinpointing the key environment issues. (2) It proposes age-friendly design strategies for various functional areas of Nanjing South Railway Station. (3) It introduces an age-friendly module combination design system, which including basic type I, enhanced type II, and optimized type III, in order to meet the demands for six levels of high-speed railway stations in China. This study promotes the age-friendly transformation of environments at a high-speed railway station, offering theoretical foundations and methodological references for constructing an age-friendly environment from a healthy ageing perspective.