Accurate trajectory forecasting and well-defined predictive uncertainty are crucial for reliable, safety-critical applications such as autonomous driving. Most trajectory prediction approaches provide point estimates only, while uncertainty-aware approaches typically quantify uncertainty only in the trajectory space. In physics-aware approaches, uncertainty in the predicted motion variables should be explicitly modeled and propagated through the vehicle dynamics. Otherwise, the resulting trajectory-space uncertainty may not fully reflect the variability introduced by the underlying motion prediction. Therefore, in this work, uncertainty-aware extensions of X-TRACK (X-TRACK-DE and X-TRACK-MCD), a physics-aware trajectory prediction framework, are proposed. The proposed framework predicts future vehicle motion variables and models both aleatoric and epistemic uncertainties by propagating motion space uncertainty to trajectory space. Additionally, conformal prediction is applied to the trajectory space predictive covariance to construct uncertainty regions targeting a desired marginal coverage level. Evaluation on the highD dataset shows that X-TRACK-DE improves trajectory prediction accuracy over the deterministic baseline, while both uncertainty-aware variants provide predictive uncertainty that can be conformally calibrated to the desired marginal coverage level.
Figures & tables
Figure 1: Overview of the uncertainty-aware X-TRACK framework. Aleatoric uncertainty is estimated by sampling from the predicted motion distributions, and epistemic uncertainty is obtained using MC Dropout or Deep Ensembles. The sampled vehicle motion variables are propagated through the physics-based kinematic layer to obtain uncertainty in trajectory space. To obtain calibrated trajectory uncertainty regions, conformal prediction is applied.
Architecture
ADE ↓
FDE ↓
minADE ↓
minFDE ↓
X-TRACK ( Chugh et al., 2025 )
0.56
1.76
-
-
X-TRACK-MCD (Ours)
0.54
1.79
0.20
0.41
X-TRACK-DE (Ours)
0.44
1.49
0.15
0.33
MHA-LSTM ( Messaoud et al., 2021 )
1.97
4.72
-
-
iNATran ( Chen et al., 2022 )
1.84
3.95
-
-
GFTNNv2 ( Neumeier et al., 2023 )
0.92
2.20
-
-
Table 1: ADE and FDE (in meters) evaluated at a 5s prediction horizon for the evaluated models
Architecture
1s
2s
3s
4s
5s
X-TRACK ( Chugh et al., 2025 )
0.10
0.31
0.71
1.31
2.16
X-TRACK-MCD (Ours)
0.06
0.22
0.66
1.34
2.23
X-TRACK-DE (Ours)
0.04
0.16
0.51
1.09
1.87
MHA-LSTM ( Messaoud et al., 2021 )
0.71
1.62
2.85
4.31
6.06
iNATran ( Chen et al., 2022 )
0.88
1.62
2.35
3.58
4.95
GFTNNv2 ( Neumeier et al., 2023 )
0.47
0.61
1.05
1.75
2.69
Table 2: Comparison of the proposed variants with the baseline models evaluated in the considered highway trajectory prediction setting in terms of RMSE at different prediction horizons.
Metric
X-TRACK MCD
X-TRACK DE
cVMDx
NLL ↓
0.47
0.51
11.32
ECE ↓
0.17
0.12
0.10
Pearson Correlation ( ρ ) ↑
0.34
0.33
0.05
Mean Predictive Uncertainty ( m2 )
1.32
0.75
4.04
Miss Rate (MR) @ 2m↓
0.02
0.01
0.31
CP Coverage@ 95%
95.72%
95.39%
-
Table 3: Uncertainty quantification and calibration performance of the evaluated uncertainty-aware trajectory prediction approaches.
Figure 2: Qualitative comparison of ground truth with deterministic X-TRACK and predictive means of X-TRACK-MCD and X-TRACK-DE .
Figure 3: Decomposition of uncertainty into individual components for both variants.
Figure 4: Comparing empirical coverage and nominal confidence for raw predictive distributions of X-TRACK-MCD and X-TRACK-DE .
Table 4: Architectural modification of X-TRACK for the Deep Ensemble members.
Architecture
ADE ↓
FDE ↓
Pre-CP C@95% ↑
ECE ↓
Homogeneous Ensemble
0.65
1.85
25.2%
0.25
Heterogeneous Ensemble
0.58
1.72
42.4%
0.08
Appendix
Table 5: Comparison of homogeneous and heterogeneous ensembles to assess the impact of architectural diversity.
X-TRACK-MCD
X-TRACK-DE
Metric
Pre-CP
Post-CP
Pre-CP
Post-CP
Coverage@95% ↑
67.47%
95.72%
62.01%
95.39%
MPIW ↓
2.24
2.61
1.57
2.11
ECE ↓
0.17
0.11
0.12
0.11
Appendix
Table 6: Effect of conformal prediction on the uncertainty-aware variants.
Figure 5: Comparison of total predictive uncertainty for X-TRACK-MCD and X-TRACK-DE over different prediction horizons.
Figure 6: Total predictive uncertainty in trajectory space over the prediction horizon for X-TRACK-MCD and X-TRACK-DE. The same mean uncertainty is shown using (a) linear, (b) semi-logarithmic, and (c) log-log scales.
Figure 7: Comparison of predictive multiple trajectories obtained by X-TRACK-DE and X-TRACK-MCD.
Figure 8: Qualitative comparison of ground-truth trajectories with deterministic X-TRACK and the predictive means of its uncertainty-aware variants.
Figure 9: Decomposition of trajectory space predictive uncertainty (different scales) into aleatoric, epistemic, and total components for X-TRACK-MCD and X-TRACK-DE.
Most trajectory forecasting models are trained on clean annotated histories, and are often evaluated under the same idealized assumption, although practical deployments rely on trajectories produced by imperfect multi-object trackers. The real-world observations exhibit localization jitter, missed or unstable detections, and data-association ambiguity, which are usually either ignored or removed through denoising. This paper instead treats tracking-derived reliability cues as an informative signal to be propagated to the predictor. We propose a plug-in uncertainty-aware formulation in which each observed state is encoded as an uncertain state representation, modeled by a Gaussian distribution whose covariance combines detection-level localization uncertainty and association-level ambiguity through the law of total variance. Existing backbones are adapted with minimal architectural changes: input trajectories are represented as Gaussian observations, and predicted trajectories are produced as Gaussian forecasts rather than deterministic coordinates. To train predictors that remain robust under structured observation noise, we combine temporally correlated Ornstein-Uhlenbeck perturbations with response-based knowledge distillation from a teacher trained on clean trajectories. Experiments on Oxford Town Centre and VIRAT using real tracker outputs, together with a complementary ETH/UCY pseudo-detection protocol, show that the proposed formulation improves displacement accuracy and the reliability-sharpness trade-off of probabilistic forecasts.
Stephane Da Silva Martins, Victor Petrovic, Emanuel Aldea +1
SATIE – CNRS UMR 8029, Université Paris-Saclay, France · ENS Paris-Saclay, Université Paris-Saclay, France
Accurate trajectory forecasting of surrounding traffic participants is a core capability for autonomous driving, enabling vehicles to anticipate behavior and plan safe maneuvers. We observe that current state-of-the-art forecasting models on Argoverse 2 and the Waymo Open Motion Dataset tailor their training objectives to the different benchmark metrics. Because these metrics encourage conflicting behavior, we propose a paradigm change for trajectory forecasting: training models with metric-agnostic probabilistic objectives and treating metric optimization as a downstream task applied to the predictive distribution. Concretely, we introduce Trajectory Distribution Evaluation (TraDiE) policies, metric-specific policies that map a predictive distribution to the set of K trajectories and confidences required by trajectory forecasting metrics. We evaluate this framework by introducing DONUT-NLL, which adapts the training objective of the state-of-the-art trajectory forecasting model DONUT to directly optimize the predictive distribution. Using our policies, DONUT-NLL achieves state-of-the-art results on all metrics of the Waymo motion prediction benchmark.
Markus Knoche, Daan de Geus, Bastian Leibe
RWTH Aachen University, Germany · Eindhoven University of Technology, Netherlands
Accurate trajectory prediction is critical for safe autonomous navigation in crowded environments. While many trajectory predictors output Gaussian distributions to represent the multi-modal distribution over future pedestrian positions, the reliability of their confidence levels often remains unaddressed. This limitation can lead to unsafe or overly conservative motion planning when the predictor is integrated with an uncertainty-aware planner. Existing Gaussian trajectory predictors primarily rely on the Negative Log-Likelihood loss, which is prone to predict over- or under-confident distributions, and may compromise downstream planner safety. This paper introduces a novel loss function for calibrating prediction uncertainty which leverages Kernel Density Estimation to estimate the empirical distribution of confidence levels. The proposed formulation enforces consistency with the properties of a Gaussian assumption by explicitly matching the estimated empirical distribution to the Chi-squared distribution. To ensure accurate mean prediction, a Mean Squared Error term is also incorporated in the final loss formulation. Experimental results on real-world trajectory datasets show that our method significantly improves the reliability of confidence levels predicted by different State-Of-The-Art Gaussian trajectory predictors. We also demonstrate the importance of providing planners with reliable probabilistic insights (i.e. calibrated confidence levels) for collision-free navigation in complex scenarios. For this purpose, we integrate Gaussian trajectory predictors trained with our loss function with an uncertainty-aware Model Predictive Control on scenarios extracted from real-world datasets, achieving improved planning performance through calibrated confidence levels.
Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61820 USA · Department of Mathematical and Computational Sciences, University of Toronto, Toronto, Canada