Ayalon Model
Real-time physical impact measurement — Highway 20, Israel
Overview
The Ayalon Model is a real-time physical impact monitor for Highway 20 (Ayalon Freeway) in Tel Aviv, Israel. It measures the systemic cost of traffic congestion by computing excess time, wasted fuel, CO₂ emissions, and direct financial loss — all derived from live traffic data.
This is not a prediction model. It is a measurement instrument that transforms observed traffic conditions into physical counters with full provenance metadata. Every data point traces back to its source.
What it measures
Total extra time all vehicles spend due to congestion vs free-flow speed (90 km/h).
Extra fuel burned during delay — idle and stop-go driving at 0.8 L/h × 1.5 stop-go factor.
Carbon dioxide implied by excess fuel consumption (2.31 kg CO₂ per litre gasoline).
Direct fuel cost from congestion. Fuel price fetched from Gov.il monthly notice.
Data sources
| Source | Data | Cadence | Key required |
|---|---|---|---|
| TomTom Traffic Flow API v4 | Real-time speed, travel time per segment | ~5 min (cache TTL) | Yes (TOMTOM_API_KEY) |
| Open-Meteo / Sviva | Air quality (PM2.5, AQI) | ~10 min | No |
| Gov.il fuel notice | Consumer gasoline 95 price (ILS/L) | Monthly (cached 24h) | No |
Methodology
The model probes three canonical segments along Highway 20 (La Guardia, HaShalom, Arlozorov interchanges). For each segment:
- Polyline length is computed via Haversine distance on the TomTom coordinate response.
- Free-flow travel time is derived from posted speed (90 km/h).
- Delay = observed travel time − free-flow travel time (clamped ≥ 0).
- Fuel excess = delay × estimated vehicles × idle rate × stop-go factor.
- CO₂ = fuel excess × 2.31 kg/L. Leakage = fuel excess × current fuel price.
Constants are frozen in LOCKED_CONSTANTS.json (Appendix A, v1.2).
Every model run produces a provenance record with pipeline run ID, source IDs,
and data timestamps. History is stored in a local SQLite database.
Provenance
Every measurement cycle records:
- Model version: 1.0-freeze
- Constants version: Appendix A v1.2
- Data timestamp: ISO-8601 UTC from TomTom response
- Source IDs: traffic, air quality, fuel — each traced to provider
- Pipeline run ID: UUID v4, unique per measurement
Protocol reference: DKP-5-TRANSPORT-001, Layer L5 — Transport / Physical Truth.