Emergency Medical Service Accessibility Equity Across Higher- and Lower-Intensity Residential Communities: A Subdistrict Screening Exercise in Beijing

Urban renewal decisions require evidence on both absolute emergency medical services (EMS) access and relative differences between residential communities. We compared 13,266 residential communities across 190 Beijing subdistricts using a modified two-leg two-step floating catchment area (2SFCA) measure of potential opportunity and two-leg EMS vehicle travel time. Floor area ratio (FAR) was used as a proxy for development intensity: communities with FAR ≥ 2.0 were classified as higher-intensity and those with FAR < 2.0 as lower-intensity. A percentile-based Fairness index compared within-subdistrict distributions for both accessibility dimensions, and the classification was repeated at FAR = 3.0 as a threshold-sensitivity check. A paired screening identified subdistricts where lower-intensity communities had relative advantages on both measures; these locations may warrant follow-up review of higher-intensity communities, while low-access communities in either group require attention regardless of index direction. Under FAR = 2.0, the mean Fairness indices were −0.023 for potential opportunity and 0.004 for vehicle travel time; they were positively correlated (Pearson r = 0.805). Seventy-one subdistricts were high-rise-friendly and 65 low-rise-friendly, while 17 and 16 entered Tier I and Tier II double-disadvantage screening. With FAR = 3.0, 147 subdistricts were estimable, friendly-type agreement fell to 51.02%, and Tier I/Tier II Jaccard indices were 0.130 and 0.087. The results indicate that relative equity patterns are jointly associated with opportunity and travel-time accessibility but are sensitive to the operational FAR threshold. The proposed workflow translates the findings into a transparent, reproducible screening sequence for urban-renewal review. The framework can support transparent, subdistrict-level prioritization for field verification in urban-renewal review.