Investigating the link between road network and congestion for highly congested cities

Policy transfer is an efficient strategy for urban policymaking. When transferring policies for mitigating urban traffic congestion, the unique city-specific characteristics of urban traffic necessitate a thorough investigation into the relationship between the local road network and urban traffic congestion. We investigate the role of road network features in explaining the spatial variation of congestion in seven highly congested cities worldwide. The cities are segmented into uniform square-shaped urban tiles at different spatial scales, and the road network features of these tiles are used to predict the spatial variation of congestion. We study the feature importance at each scale and determine the direction of influence of these features, thereby characterising their role as alleviating or exacerbating features. For a given city, the features which retain their alleviation or exacerbation role across scales are deemed actionable. While some features were found to be actionable across several cities, significant variations, including role reversal, were found across cities, thus underscoring the need to leverage the context-specificity of urban traffic to tailor our congestion mitigation efforts.