Walkability
Your task: build a walkability measure for Madrid, grounded in real research.
The thresholds come from Cerin et al. (2022), who studied the relationship between urban characteristics and physical activity across 14 cities. Their findings suggest specific density thresholds that support walking:
- At least 100 street intersections per km2;
- At least 28 public transport stops per km2;
- At least 5,700 people per km2.
These thresholds correspond to an 80% probability of residents walking for transport.
Cerin, E., Sallis, J.F., Salvo, D. et al. (2022). Determining thresholds for spatial urban design and transport features that support walking to create healthy and sustainable cities: findings from the IPEN Adult study. The Lancet Global Health, 10(6), e866-e874. Open access (PMC) | ScienceDirect
The original study defines neighbourhoods using network-based buffers (the area reachable along streets within 1km). In this exercise, we use circular buffers with an equivalent area instead. This is simpler to calculate in QGIS and gives broadly similar results, but it’s worth knowing the difference.
Part of the point here is learning to find the right tools in QGIS and figure out how to chain them together. You won’t be told which tool to use at each step. Explore the Processing Toolbox, try things, and see what works. That process of discovering and combining tools is how real GIS work gets done.
Read through the relevant parts of the paper before starting. Understanding where the thresholds come from will help you interpret your results.