Assessing Ecological Inequality in Urban Green Space Distribution Along Road Networks in Riyadh City

Urban green spaces (UGSs) are vital ecological infrastructure supporting climate resilience, public health, and environmental equity. Despite UGS’s importance, the distribution of UGS in rapidly growing desert cities is wildly disproportionate, as evidenced by a recent study that links UGS availability with road hierarchy using the Road Buffer Framework. Using Landsat 8-derived UGS (overall accuracy = 0.885; Kappa = 0.853), OpenStreetMap Roads, and WorldPop Population Data, this study found that UGS availability per capita is very low across all road classifications (0.020–0.033 m2/person) and falls significantly short of the World Health Organization’s (WHO) recommendation of 9 m2/person. Primary roads only marginally improved based on distance from roadways (0.026–0.032 m2/person), and secondary roads are experiencing little to no change (0.025–0.026 m2/person). Further, Tertiary roads show the most significant loss, with only 0.022 m2/person available within the 0–300 m buffers containing the most people. In addition, urban green spaces are still significantly inequitable, as demonstrated by Gini coefficient results of >0.80, peaking at 0.895, indicating that UGS availability per capita is substantially below international benchmarks. Therefore, the findings highlight the need of incorporating roadside greening, small park areas, and greenways into our transportation planning efforts to support the UN’s Sustainable Development Goals (SDG) 3, 10, 11, and 13.