85 lines
3.1 KiB
Markdown
85 lines
3.1 KiB
Markdown
# Independent Rule-Based VSL Baselines
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The project includes three deterministic non-learning VSL baselines. They are
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kept separate on purpose, so each one tests one traffic-control idea instead of
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mixing several rules into a single hand-crafted policy.
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## 1. `occ_rule_vsl`
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Local occupancy/speed hysteresis baseline.
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The rule observes each controlled segment independently. When occupancy rises
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or local speed drops, the displayed speed limit is reduced in stages. When
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occupancy falls below a lower release threshold and speed recovers, the segment
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returns to the highest legal action. The lower release threshold creates
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hysteresis and avoids frequent switching around one threshold.
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Literature basis:
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- Smulders, S. (1990). Control of freeway traffic flow by variable speed signs.
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Transportation Research Part B: Methodological, 24(2), 111-132.
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doi:10.1016/0191-2615(90)90023-R.
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## 2. `bottleneck_rule_vsl`
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Downstream bottleneck pre-control baseline.
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The rule does not react only to the current segment. For each controlled
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segment, it looks downstream over a short corridor window. If the downstream
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window contains high occupancy or low speed, the upstream segment is capped
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before traffic reaches the forming bottleneck. This isolates the idea of
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coordinated upstream flow moderation.
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Literature basis:
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- Hegyi, A., De Schutter, B., and Hellendoorn, J. (2005). Model predictive
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control for optimal coordination of ramp metering and variable speed limits.
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Transportation Research Part C: Emerging Technologies, 13(3), 185-209.
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doi:10.1016/j.trc.2004.08.001.
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## 3. `harmonization_rule_vsl`
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Speed-harmonization baseline.
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The rule compares the measured speed of a segment with its immediate downstream
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segment. If the downstream segment is much slower, the upstream speed limit is
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reduced to smooth the speed transition. This isolates the safety-oriented speed
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harmonization idea without adding occupancy or bottleneck logic.
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Literature basis:
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- Allaby, P., Hellinga, B., and Bullock, M. (2007). Variable speed limits:
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Safety and operational impacts of a candidate control strategy for freeway
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applications. IEEE Transactions on Intelligent Transportation Systems, 8(4),
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671-680. doi:10.1109/TITS.2007.908562.
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## Shared Display Constraints
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All three baselines share only engineering display constraints:
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- speed limits are selected from the same discrete action set as learning
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models;
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- temporal changes are capped to avoid abrupt one-step jumps;
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- adjacent segment changes are capped to avoid unrealistic spatial discontinuity.
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These constraints are not additional control objectives; they only keep displayed
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VSL signs physically plausible and comparable across baselines.
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## Run Commands
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Run one rule baseline:
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```powershell
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uv run python -m training.run_model --model occ_rule_vsl
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uv run python -m training.run_model --model bottleneck_rule_vsl
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uv run python -m training.run_model --model harmonization_rule_vsl
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```
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Run all three:
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```powershell
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uv run run_all_training.py --models occ_rule_vsl bottleneck_rule_vsl harmonization_rule_vsl
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```
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The default multi-model run now includes all three independent rule baselines.
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