A Multi-Resolution Multi-Domain Pre-Training Framework for Universal Traffic Forecasting
Organizations: PDL Lab, National University of Defense Technology, Hunan, China · Shandong University, Shandong, China · HKUST (GZ) · Didichuxing Co. Ltd, Beijing, China ·
Abstract
Spatio-temporal traffic data are central to intelligent transportation systems, yet their heterogeneity poses significant challenges for large-scale modeling. Existing pre-trained models often rely on a homogeneous modeling paradigm to handle highly heterogeneous traffic data. This fundamental mismatch not only limits model generalization but also leads to computationally expensive and parameter-inefficient designs. To this end, we propose FlexST, a novel pre-training framework that introduces modularity and adaptivity for traffic modeling. Specifically, we first propose a multi-resolution spatio-temporal diffusion module that captures both short-term fluctuations and long-range trends, effectively reconciling inputs with divergent temporal and spatial resolutions. After that, we construct a domain-adaptive mixture-of-experts that dynamically routes data to specialized sub-networks, enabling selective knowledge transfer while preventing negative interference across diverse domains. Moreover, we devise a unified periodic encoding strategy that injects resolution- and domain-aware inductive biases to harmonize periodic inconsistencies across datasets. Extensive experiments on 23 real-world traffic datasets demonstrate that FlexST significantly outperforms state-of-the-art baselines in zero- and few-shot settings, showcasing superior generalization, adaptability and efficiency. This work offers a new direction for building general-purpose pre-trained models capable of handling the complexity and variability of urban traffic systems.
Figures & tables
| Dataset | PEMS04 | PEMS08 | Didi-SZ | Beijing Taxi | HZMetro | CHI-Bike | Beijing Subway | |||||||||||||||
| Inflow | Outflow | Inflow | Outflow | Inflow | Outflow | Inflow | Outflow | |||||||||||||||
| MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | |
| HA | 38.67 | 57.49 | 31.93 | 47.72 | 3.19 | 4.81 | 56.39 | 94.83 | 56.47 | 94.93 | 130.30 | 235.99 | 130.00 | 219.45 | 6.02 | 11.18 | 5.99 | 11.53 | 238.66 | 425.64 | 232.28 | 454.64 |
| TimesFM | 36.84 | 56.62 | 30.43 | 47.10 | 3.09 | 4.70 | 48.84 | 85.42 | 48.93 | 85.53 | 113.21 | 216.89 | 114.88 | 204.20 | 5.69 | 10.57 | 5.63 | 10.83 | 201.74 | 385.23 | 197.52 | 415.69 |
| Timer | 125.88 | 152.52 | 117.77 | 141.59 | 7.83 | 10.58 | 90.80 | 127.08 | 90.84 | 127.18 | 150.13 | 258.28 | 150.24 | 245.23 | 6.24 | 12.91 | 6.24 | 13.23 | 224.25 | 425.30 | 219.84 | 463.39 |
| Sundial | 36.56 | 55.35 | 30.20 | 46.14 | 3.18 | 4.84 | 50.90 | 88.25 | 51.01 | 88.38 | 123.18 | 221.96 | 124.59 | 221.96 | 5.85 | 10.99 | 5.82 | 11.35 | 224.25 | 425.30 | 219.84 | 463.39 |
| Dataset | PEMS04 | PEMS08 | Didi-SZ | HZMetro | ||||||
| Inflow | Outflow | |||||||||
| MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | |
| HA | 123.73 | 160.18 | 104.67 | 137.75 | 5.04 | 6.86 | 106.77 | 193.77 | 106.63 | 183.58 |
| TimesFM | 95.63 | 132.00 | 72.03 | 105.05 | 4.28 | 5.96 | 87.759 | 218.089 | 78.832 | 182.676 |
| Timer | 111.52 | 132.88 | 106.06 | 128.96 | 6.39 | 8.82 | 142.714 | 242.061 | 145.531 | 236.142 |
| Sundial | 101.46 | 136.81 | 67.46 | 97.97 | 4.82 | 6.50 | 159.44 | 313.21 | 157.96 | 304.78 |
| Dataset | PEMS08 | Didi-SZ | TrafficZZ | NYC-Taxi | CHI-Taxi | NYC-Bike | CHI-Bike | |||||||||||||||
| Inflow | Outflow | Inflow | Outflow | Inflow | Outflow | Inflow | Outflow | |||||||||||||||
| MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | |
| HA | 32.19 | 48.07 | 3.17 | 4.79 | 1.46 | 2.09 | 16.99 | 38.73 | 25.15 | 51.74 | 4.42 | 11.53 | 4.80 | 12.46 | 14.47 | 10.48 | 14.30 | 24.16 | 6.16 | 11.54 | 5.99 | 11.54 |
| Informer | 69.10 | 94.23 | 3.05 | 4.70 | 1.09 | 1.79 | 18.54 | 41.33 | 30.07 | 57.14 | 4.13 | 13.15 | 4.62 | 14.81 | 13.45 | 24.82 | 13.42 | 24.50 | 4.37 | 8.89 | 4.27 | 8.76 |
| PatchTST | 22.26 | 35.58 | 2.82 | 4.34 | 1.16 | 1.80 | 11.37 | 26.91 | 17.25 | 38.02 | 3.30 | 8.42 | 3.60 | 9.40 | 10.87 | 19.77 | 10.86 | 19.34 | 5.00 | 9.68 | 4.88 | 9.55 |
| STGCN | 28.99 | 42.40 | 3.39 | 5.09 | 1.07 | 1.69 | 17.71 | 38.17 | 28.68 | 52.78 | 3.66 | 11.17 | 4.10 | 13.04 | 11.11 | 21.87 | 11.10 | 21.66 | 3.53 | 7.24 | 3.52 | 7.18 |
| Dataset | PEMS08 | Didi-SZ | TrafficZZ | NYC-Taxi | NYC-Bike | |||||||||
| Inflow | Outflow | Inflow | Outflow | |||||||||||
| MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | MAE | RMSE | |
| HA | 105.80 | 139.29 | 4.95 | 6.75 | 1.18 | 1.66 | 13.87 | 31.39 | 20.99 | 42.47 | 11.86 | 20.41 | 11.66 | 20.04 |
| Informer | 87.83 | 118.34 | 3.69 | 5.38 | 1.09 | 1.77 | 19.56 | 43.31 | 31.40 | 59.84 | 13.45 | 24.50 | 13.37 | 24.13 |
| PatchTST | 46.88 | 73.00 | 3.35 | 5.07 | 0.59 | 0.95 | 7.31 | 18.71 | 11.45 | 27.58 | 7.44 | 14.28 | 7.68 | 14.55 |
| STGCN | 51.81 | 74.70 | 4.11 | 5.82 | 1.09 | 1.72 | 22.84 | 45.49 | 34.75 | 60.09 | 10.73 | 21.24 | 10.66 | 20.81 |
| Notation | Description |
| Graph with spatial units and adjacency matrix representing spatial connections | |
| Single-domain traffic data with observations per spatial unit , characterized by task type , temporal resolution , spatial resolution and spatial graph | |
| Time span of time series, determining its absolute duration | |
| timestamps associated with observations | |
| Spatial resolution and spatial receptive field at resolution | |
| Multi-domain traffic dataset |
| Dataset | Traffic Flow | Taxi Demand | Traffic Speed | Metro Flow | Congestion Level | Total |
| # of Regions | 1,957 | 263 | 2,676 | 564 | 524 | 3,584 |
| # of Records | 71,834,110 | 9,240,768 | 28,015,352 | 5,621,616 | 9,054,720 | 123,766,566 |
| Sampling Rate | 5T | 30T | 5T, 30T | 10T, 15T | 10T | 5T, 10T, 15T, 30T |
| Source | [ 3 , 12 ] | [ 36 ] | [ 8 , 38 ] | [ 39 , 40 ] | [ 41 ] | - |
| Dataset | PEMS04 | PEMS08 | GBA | NYC-Taxi | CHI-Taxi | Beijing Taxi | NYC-Bike | CHI-Bike | TrafficZZ | Beijing Subway | HZMetro | Didi-SZ |
| Task | Traffic Flow | Traffic Flow | Traffic Flow | Taxi Demand | Taxi Demand | Taxi Demand | Bicycle Sharing | Bicycle Sharing | Traffic Speed | Metro Flow | Metro Flow | Congestion Level |
| # of Regions | 307 | 170 | 2,352 | 263 | 77 | 1,024 | 540 | 270 | 676 | 276 | 80 | 627 |
| # of Records | 5,216,544 | 3,035,520 | 124,637,184 | 46,102,848 | 2,698,080 | 43,745,280 | 113,633,280 | 2,384,640 | 948,428 | 993,600 | 292,000 | 10,834,560 |
| Sampling Rate | 5T | 5T | 5T | 30T | 30T | 30T | 30T | 30T | 30T | 15T | 15T | 10T |
| Source | [ 3 ] | [ 3 ] | [ 12 ] | [ 36 ] | [ 36 ] | [ 8 ] | [ 36 ] | [ 37 ] | [ 8 ] | [ 38 ] | [ 40 ] | [ 41 ] |
Traffic Forecasting
Traffic forecasting predicts future flows, speeds, demand, travel times, and congestion from spatial, temporal, and contextual data.
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