---
library_name: keras
license: apache-2.0
pipeline_tag: tabular-classification
tags:
- tensorflow
- keras
- tabular
- classification
- ensemble
- transportation
model-index:
- name: imt-ml-track-ensemble-20250906-124755
  results:
  - task:
      type: tabular-classification
      name: Track classification
    dataset:
      name: MBTA Track Assignment (custom)
      type: custom
      split: validation
    metrics:
    - type: accuracy
      name: Average individual accuracy
      value: 0.5957
    - type: accuracy
      name: Best individual accuracy
      value: 0.6049
    - type: loss
      name: Average individual loss
      value: 1.2251
---

# imt-ml Track Prediction — Ensemble (2025-09-06 12:47:55)

Predicts which MBTA commuter rail track/platform a train will use, using a small tabular neural-network ensemble trained on historical assignments. This card documents the artifacts in `output/ensemble_20250906_124755`.

## Model Summary

- Task: Tabular multi-class classification (13 track classes)
- Library: Keras (TensorFlow backend)
- Architecture: 6-model ensemble (diverse dense nets with embeddings + cyclical time features); softmax outputs averaged at inference
- Inputs (preprocessed):
  - Categorical: `station_id` (int index), `route_id` (int index), `direction_id` (0/1)
  - Time (cyclical): `hour_sin`, `hour_cos`, `minute_sin`, `minute_cos`, `day_sin`, `day_cos`
  - Continuous: `scheduled_timestamp` (float seconds since epoch; normalized in-model)
- Outputs: Probability over 13 track labels (softmax)
- License: MIT

## Files in This Repo

- `track_prediction_ensemble_model_0_final.keras` … `track_prediction_ensemble_model_5_final.keras` — individual ensemble members
- `track_prediction_ensemble_model_*_best.keras` — best checkpoints during training (may match `final`)
- `training_report.md` — training configuration and metrics

Note: Ensemble training currently does not emit a `*_vocab.json`. See “Preprocessing & Vocab” below.

## Preprocessing & Vocab

Models expect integer indices for `station_id` and `route_id`, and raw `direction_id` 0/1. In training, indices are produced by lookup tables built from the dataset vocabularies. To reproduce inference exactly, you must use the same vocabularies (station/route/track) that were present at training time or ensure consistent mapping.

What to use:
- The training pipeline’s dataset loader (`imt_ml.dataset.create_feature_engineering_fn`) defines the exact feature mapping. If you need the vocab files, re-run a training or export step to generate them for your data snapshot, or save the vocab mapping alongside the model.

## Metrics (validation)

From `training_report.md`:
- Average validation loss: 1.2251
- Average validation accuracy: 0.5957
- Best individual accuracy: 0.6049
- Worst individual accuracy: 0.5812
- Ensemble accuracy stdev: 0.0087
- Dataset size: 24,832 records (310 train steps/epoch, 77 val steps/epoch)

These metrics reflect individual model performance; at inference time, average the softmax probabilities across all 6 models to produce ensemble predictions.

## Example Usage (local Python)

This snippet loads all six Keras models and averages their softmax outputs. Replace the feature values with your preprocessed tensors/arrays, ensuring they match the training feature schema and index mappings.

```python
import numpy as np
import keras

# Load ensemble members
paths = [
    "track_prediction_ensemble_model_0_final.keras",
    "track_prediction_ensemble_model_1_final.keras",
    "track_prediction_ensemble_model_2_final.keras",
    "track_prediction_ensemble_model_3_final.keras",
    "track_prediction_ensemble_model_4_final.keras",
    "track_prediction_ensemble_model_5_final.keras",
]
models = [keras.models.load_model(p, compile=False) for p in paths]

# Prepare one example (batch size 1) — values shown are placeholders.
# You must convert raw strings to indices using the same vocab mapping used in training.
features = {
    "station_id": np.array([12], dtype=np.int64),     # int index
    "route_id": np.array([3], dtype=np.int64),        # int index
    "direction_id": np.array([1], dtype=np.int64),    # 0 or 1
    "hour_sin": np.array([0.707], dtype=np.float32),
    "hour_cos": np.array([0.707], dtype=np.float32),
    "minute_sin": np.array([0.0], dtype=np.float32),
    "minute_cos": np.array([1.0], dtype=np.float32),
    "day_sin": np.array([0.433], dtype=np.float32),
    "day_cos": np.array([0.901], dtype=np.float32),
    "scheduled_timestamp": np.array([1.7260e9], dtype=np.float32),
}

# Predict per model and average probabilities
probs = [m.predict(features, verbose=0) for m in models]
avg_prob = np.mean(probs, axis=0)   # shape: (batch, num_tracks)
pred_class = int(np.argmax(avg_prob, axis=-1)[0])
print({"predicted_track_index": pred_class, "probabilities": avg_prob[0].tolist()})
```

Tip: If you have the track vocabulary used at training time, you can map `pred_class` back to its track label string by indexing into that `track_vocab` list.

## Training Data

- Source: Historical MBTA track assignments exported from Redis to TFRecord
- Features:
  - Categorical: `station_id`, `route_id`, `direction_id`
  - Temporal: hour, minute, day_of_week (encoded as sin/cos pairs)
  - Target: `track_number` (13 classes)

## Training Procedure

- Command: `ensemble`
- Num models: 6 (architectural diversity: deep, wide, standard)
- Epochs: 150
- Batch size: 64
- Base learning rate: 0.001 (varied 0.8x–1.2x per model)
- Regularization: L1/L2, Dropout, BatchNorm; cosine LR scheduling and early stopping when enabled

## Intended Use & Limitations

- Intended for assisting real-time track/platform assignment predictions for MBTA commuter rail.
- Not a safety system; always defer to official dispatch/operations.
- Sensitive to concept drift (schedule/operational changes) and to unseen stations/routes.
- Requires consistent categorical index mapping between training and inference.