Effective or useless? Assessing the impact of park entrance addition policy on green space services from the 15-min city perspective

This study investigates an innovative approach to enhance urban green space access by adding new park entrances rather than expanding the green space itself, aiming for sustainable urban development. Taking Shenzhen as a case study, we first developed a universal framework to identify potential locations for new entrances and used network analysis in ArcGIS to quantify green service improvements. Then, under the 15-min city concept, the impact on green accessibility and equity was assessed using the two-step floating catchment area (2SFCA) method and Gini coefficient analysis. Results indicate that (1) new entrances enabled 21.10% of residents to access parks with an average reduced travel distance of 214.71 m, and increased the population within a 15-min walk to parks by 7.34%. (2) This strategy proved cost-effective, serving 27.66% of residents at 1/38 the cost of creating new green spaces. (3) Furthermore, the accessible green area within a 15-min walking or cycling increased by 0.18 km2 and 1.42 km2, respectively, without affecting green equity. Our findings support the policy of adding park entrances as a feasible and efficient urban strategy, supporting Sustainable Development Goals (SDGs) 3 and 11, and the policy can be implemented across almost cities.