aiqbench analysis
TEGER introduces a novel method for maintaining calibrated predictive uncertainty in traffic forecasting by applying closed-form updates to residual covariances without retraining the underlying foundation model. This approach effectively addresses data drift in sensor behavior and demand patterns, significantly improving forecast accuracy when applied post-hoc to frozen models like Chronos. The technique demonstrates that test-time corrections can refresh joint uncertainty estimates at negligible computational cost while preserving learned correlation structures.
Teger: Spatiotemporal Covariance for Probabilistic Traffic Forecasting
arXiv:2605.18068v2 Announce Type: replace-cross Abstract: Traffic conditions drift -- demand patterns, incident dynamics, and sensor behavior shift over a deployment's lifetime -- so a joint uncertainty estimate fit once at training time and left static will miscalibrate as conditions change. We present TEGER, a residual covariance model that keeps a forecaster's joint predictive uncertainty current at test time through closed-form updates, not retraining. A fixed sensor graph supplies a low-dimensional spatial precision factor encoding which sensors' errors move together; at inference, Gaussian conditioning corrects The next forecast's mean and covariance from only the most recently observed residuals, and an exponential moving-average volatility term rescales marginal uncertainty to track local drift while preserving the learned correlation structure. Neither update touches the forecasting backbone's weights, so the same mechanism attaches to a frozen time-series foundation model: no gradient passes through it, turning a static point forecast into one with continually refreshed, correlated uncertainty at negligible added cost. In four traffic datasets, the fixed-graph covariance improves 60-minute $CRPS_{sum}$ over a temporal-only baseline in different configurations of the backbone and datasets. Applied post hoc to a frozen time-series foundation model, Chronos, the same test-time correction reduces $CRPS_{sum}$ from 0.1798 to 0.1736 without foundation-model fine-tuning. These results support closed-form test-time residual correction, rather than a covariance fixed once at training time.
Abstract:Traffic conditions drift -- demand patterns, incident dynamics, and sensor behavior shift over a deployment's lifetime -- so a joint uncertainty estimate fit once at training time and left static will miscalibrate as conditions change. We present TEGER, a residual covariance model that keeps a forecaster's joint predictive uncertainty current at test time through closed-form updates, not retraining. A fixed sensor graph supplies a low-dimensional spatial precision factor encoding which sensors' errors move together; at inference, Gaussian conditioning corrects The next forecast's mean and covariance from only the most recently observed residuals, and an exponential moving-average volatility term rescales marginal uncertainty to track local drift while preserving the learned correlation structure. Neither update touches the forecasting backbone's weights, so the same mechanism attaches to a frozen time-series foundation model: no gradient passes through it, turning a static point forecast into one with continually refreshed, correlated uncertainty at negligible added cost. In four traffic datasets, the fixed-graph covariance improves 60-minute $CRPS_{sum}$ over a temporal-only baseline in different configurations of the backbone and datasets. Applied post hoc to a frozen time-series foundation model, Chronos, the same test-time correction reduces $CRPS_{sum}$ from 0.1798 to 0.1736 without foundation-model fine-tuning. These results support closed-form test-time residual correction, rather than a covariance fixed once at training time.
Machine Learning (cs.LG); Artificial Intelligence (cs.AI)
arXiv:2605.18068 [cs.LG]
(or arXiv:2605.18068v2 [cs.LG] for this version)
https://doi.org/10.48550/arXiv.2605.18068 Focus to learn more arXiv-issued DOI via DataCite
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.
Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.
Full text under the publisher's open licence · 306 words
Related coverage

Prophet vs NeuralProphet vs TimeGPT vs Chronos: A Practical Comparison
Analytics Vidhya · Jun 9, 2026

TimesFM-3: A zero-shot foundation model for multivariate forecasting
Google Research · Aug 31, 2026

Google AI Releases TimesFM-3: A 330M Parameter Zero-Shot Foundation Model For Multivariate Time Series Forecasting
MarkTechPost · Aug 31, 2026
MercerFlow: Flow Matching in a Kernel-Induced Latent Space for Probabilistic Forecasting
arXiv · Oct 7, 2026