  Predicting traffic incident risks at granular spatiotemporal levels is
challenging. The datasets predominantly feature zero values, indicating no
incidents, with sporadic high-risk values for severe incidents. Notably, a
majority of current models, especially deep learning methods, focus solely on
estimating risk values, overlooking the uncertainties arising from the
inherently unpredictable nature of incidents. To tackle this challenge, we
introduce the Spatiotemporal Zero-Inflated Tweedie Graph Neural Networks
(STZITD-GNNs). Our model merges the reliability of traditional statistical
models with the flexibility of graph neural networks, aiming to precisely
quantify uncertainties associated with road-level traffic incident risks. This
model strategically employs a compound model from the Tweedie family, as a
Poisson distribution to model risk frequency and a Gamma distribution to
account for incident severity. Furthermore, a zero-inflated component helps to
identify the non-incident risk scenarios. As a result, the STZITD-GNNs
effectively capture the dataset's skewed distribution, placing emphasis on
infrequent but impactful severe incidents. Empirical tests using real-world
traffic data from London, UK, demonstrate that our model excels beyond current
benchmarks. The forte of STZITD-GNN resides not only in its accuracy but also
in its adeptness at curtailing uncertainties, delivering robust predictions
over short (7 days) and extended (14 days) timeframes.

Machine Learning;Artificial Intelligence;Computers and Society