AdaST: Adaptive Coupling for Spatial-Temporal Forecasting
Authors: Zhenyu Lei, Chenghao Liu, Yushun Dong, Qi R. Wang, Jundong Li
Organizations: University of Virginia Charlottesville, VA, USA · Datadog Paris, France · Florida State University Tallahassee, FL, USA · Northeastern University Boston, MA, USA
Spatial-temporal (ST) forecasting underpins many real-world systems such as traffic, climate, and energy networks. While existing methods implicitly assume strong spatiotemporal coupling, we observe that real-world ST data exhibits distinct coupling regimes, ranging from temporal-dominated and spatial-dominated to strongly coupled patterns. This mismatch causes current models to suffer from spurious dependencies and degraded performance when one correlation dominates. To overcome this limitation, we aim to dynamically modulate spatial and temporal modeling based on the data's inherent coupling structure. However, three key challenges exist: unknown coupling structure, heterogeneous coupling dynamics, and suboptimal spatial modeling. We propose AdaST, an adaptive ST forecasting framework that tackles these challenges through a decompose-recompose paradigm. AdaST factorizes inputs into components capturing different coupling patterns using heterogeneity-aware experts. Each component is processed by role-aligned modules, and a correlation-informed adaptive recomposer integrates them for final prediction. Extensive experiments confirm that AdaST significantly outperforms state-of-the-art baselines, validating the necessity of an adaptive approach.
Figures & tables
Correlation
TD
SD
SC
Temporal
0.63±0.07
0.25±0.01
0.54±0.05
Spatial
−0.05±0.06
0.33±0.12
0.21±0.02
Table 1: Average temporal and spatial correlation coefficient in three synthetic datasets. Bold values indicate dominant correlations matching the intended coupling regime.
Figure 1 : Performance of different architectures on synthetic datasets with known coupling structures. Darker colors indicate lower normalized MAE.
Figure 2 : The overall framework of AdaST. Different colors denote different components.
Dataset
PurpleAir
PEMS04
PEMS07
PEMS08
MAE
RMSE
MAPE
MAE
RMSE
MAPE
MAE
RMSE
MAPE
MAE
RMSE
MAPE
HI
3.430
5.983
72.52%
42.35
61.66
29.92%
49.03
71.18
22.75%
36.66
50.45
21.63%
DeepAR
0.994
1.817
32.48%
20.64
32.35
14.28%
22.00
35.44
9.31%
16.80
26.38
10.66%
NBeats
0.511
1.100
23.30%
25.30
39.65
17.66%
26.14
42.72
11.37%
18.90
31.39
12.11%
GWNet
0.514
1.012
23.51%
18.80
30.14
13.19%
20.47
33.47
8.61%
14.67
23.55
9.46%
DCRNN
0.656
1.268
26.99%
19.63
31.26
13.59%
21.16
34.14
9.02%
15.22
24.17
10.21%
Table 2 : Main results on PurpleAir and PEMS benchmarks. The best and second-best scores are highlighted in bold and underlined . AdaST achieves the best performance across all datasets.
Dataset
PurpleAir
PEMS07
MAE
RMSE
MAPE
MAE
RMSE
MAPE
w/o En
0.519
1.072
23.79%
19.44
32.84
8.49%
w/o Eh
0.495
0.999
22.50%
20.39
34.14
8.68%
w/o Ew
0.498
1.023
22.85%
19.21
32.63
8.07%
w/o Ea
0.516
1.075
23.47%
20.16
33.23
11.26%
SpaAtt
0.518
1.072
23.42%
19.35
32.93
8.11%
Table 3: Ablation study on PurpleAir and PEMS07. Removing each component results in performance drop.
Figure 3 : Average gate scores of different datasets, revealing data-specific coupling structures.
Figure 4 : Gate scores across different time periods and locations, illustrating dynamic coupling.
Figure 5 : T-SNE visualization of learned representations for temporal (T), spatial (S), and spatial-temporal-coupling (ST) components, demonstrating clear separation and effective disentanglement.
Appendix figures & tables10 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 6 : Visualization of three synthetic datasets with distinct coupling structures: (a) Temporal-Dominated (TD), (b) Spatial-Dominated (SD), and (c) Strongly-Coupled (SC).
Figure 7 : Temporal correlation (ACF) analysis: TD data exhibits strong autocorrelation while SD data shows weak temporal dependencies.
Figure 8 : Spatial correlation (Pearson) analysis: SD data exhibits the strongest spatial dependencies while TD data shows negligible spatial correlation.
Model
PEMS04
PEMS07
PEMS08
PurpleAir
SpaMixer
233 s
1154 s
141 s
66 s
SpaAtt
341 s
2160 s
220 s
134 s
Speedup
1.5×
1.9×
1.6×
2.0×
Appendix
Table 4 : Average training time per epoch (seconds) comparing spatial mixer and spatial attention.
Method
ExchangeRate
ETTh1
METR-LA
PurpleAir
PEMS08
Avg. Rank
MAE / Rank
MAE / Rank
MAE / Rank
MAE / Rank
MAE / Rank
PatchTST
0.073 / 1
0.461 / 4
4.762 / 5
0.505 / 2
22.07 / 5
3.4
DLinear
0.077 / 3
0.444 / 2
4.820 / 6
0.525 / 3
22.51 / 6
4.0
STID
0.075 / 2
0.466 / 5
3.146 / 3
0.563 / 4
14.21 / 4
3.6
STNorm
0.108 / 5
0.492 / 6
3.153 / 4
0.574 / 5
15.41 / 3
4.6
HimNet
0.124 / 6
0.458 / 3
3.131 / 2
0.574 / 5
13.52 / 2
3.6
Appendix
Table 5 : Results on additional benchmarks. Best and second-best scores are in bold and underlined .
Variant
PEMS04
PEMS08
MAE
RMSE
MAPE
MAE
RMSE
MAPE
w/o En
18.45
29.93
12.76%
13.68
23.37
9.64%
w/o Eh
18.58
30.15
12.42%
14.65
23.94
9.51%
w/o Ew
18.35
29.88
12.68%
13.60
23.36
9.25%
w/o Ea
18.36
29.96
12.23%
13.70
23.70
9.03%
SpaAtt
18.28
30.15
12.28%
13.51
23.26
9.03%
Appendix
Table 6 : Ablation study on PEMS04 and PEMS08.
Figure 9 : Normalized correlation measures across datasets, further validating the adaptive recomposition mechanism. Strong correspondence with gate scores in Figure 3 confirms that correlation measures reliably reflect each component’s information content.
Figure 10 : Fine-grained temporal visualization (1-day span) of predictions and gate scores for 2 locations in PEMS07. More accurate predictions correspond to more dynamic gate score trajectories.
Figure 11 : Fine-grained temporal visualization (10-hour span) of predictions and gate scores for 2 locations in PEMS07. Location 0 achieves better accuracy alongside more adaptive gate score dynamics than location 1.
Figure 12 : Heatmap of gate scores across 160 spatial locations, showing a globally stable coupling structure with local variations that motivate the use of spatial heterogeneity experts.
Shenzhen Ubiquitous Data Enabling Key Lab Shenzhen International Graduate School, Tsinghua University, Shenzhen, China · School of Computer Science and Engineering University of Electronic Science and Technology of China, Chengdu, China