Scalable Learning of Segment-Level Traffic Congestion Functions
This addresses the problem of scalable traffic modeling for urban planners and transportation systems, though it is incremental as it builds on existing neural network methods.
The authors developed a data-driven framework that learns a single black-box function to model traffic congestion across all road segments in a metropolitan area, achieving strong generalization performance on unobserved segments and zero-shot transfer between cities, with competitive results on highway roads but room for improvement on arterial roads.
We propose and study a data-driven framework for identifying traffic congestion functions (numerical relationships between observations of traffic variables) at global scale and segment-level granularity. In contrast to methods that estimate a separate set of parameters for each roadway, ours learns a single black-box function over all roadways in a metropolitan area. First, we pool traffic data from all segments into one dataset, combining static attributes with dynamic time-dependent features. Second, we train a feed-forward neural network on this dataset, which we can then use on any segment in the area. We evaluate how well our framework identifies congestion functions on observed segments and how it generalizes to unobserved segments and predicts segment attributes on a large dataset covering multiple cities worldwide. For identification error on observed segments, our single data-driven congestion function compares favorably to segment-specific model-based functions on highway roads, but has room to improve on arterial roads. For generalization, our approach shows strong performance across cities and road types: both on unobserved segments in the same city and on zero-shot transfer learning between cities. Finally, for predicting segment attributes, we find that our approach can approximate critical densities for individual segments using their static properties.