Why small blocks make a better 15-minute living circle: Evidence from Turin and Tangshan

The impact of block size on travel behavior is crucial in low-carbon transportation and urban planning. While existing studies suggest that small-block cities have higher accessibility and promote walking and cycling, they rarely address the role of service facilities. This study utilizes data from 4696 blocks and over 50,000 POIs across 16 categories in big-block Tangshan, China, and small-block Turin, Italy, to compare the facility layout of their 15-min living circles and examine how block size influences service facility distribution. It is found that Turin's smaller blocks show a more effective 15-min living-circle pattern, with better accessibility, greater diversity, and a greater number of independent facilities. This is attributed to the earlier development, integrated land-use patterns, denser roads, and short facility service radius. It is suggested that urban renewal efforts of big blocks should focus on enhancing block-level road networks, and increasing service facilities around residential road or in the block center to create livable and green travel-friendly living circles.