{
  "schema_version": "1.0",
  "publication": "Victorian Freight Network Intelligence",
  "publisher": "Spotswood Trailers / Traffic Analytics",
  "publication_status": "Independent analytical platform; not an official VTA or Victorian Government publication.",
  "methodology_release_date": "2026-08-07",
  "generated_at": "2026-08-06T22:42:19.291213+00:00",
  "governed_release": {
    "stage22": "22.0.1",
    "stage23a4": "23A.4.0",
    "stage23a4_freeze_id": "VTA_STAGE23A4_P85_20251101_20260521",
    "reference_start": "2025-11-01",
    "reference_end": "2026-05-21",
    "reference_classification": "MIXED_PRE_OPENING_OPENING_TRANSITION_EARLY_OPERATION",
    "west_gate_tunnel_opening_date": "2025-12-14",
    "pre_opening_nights": 43,
    "on_or_after_opening_nights": 159
  },
  "source_semantics": {
    "tirtl_passing": "One classified detector observation at a monitored site-heading; not a unique truck, load or journey.",
    "scats_movement": "Signal-derived traffic movement observation; not necessarily a unique vehicle count.",
    "official_tirtl_source": "https://opendata.transport.vic.gov.au/dataset/tirtl-traffic-counts"
  },
  "governed_population": {
    "tier_a_headings": 269,
    "tier_b_headings": 12,
    "tier_c_headings": 2,
    "paired_sites": 119,
    "reference_ready_heading_hours": 2152,
    "complete_speed_hours": 374900,
    "eligible_heading_nights": 46697,
    "eligible_pressure_observations": 372586
  },
  "controlled_disclosures": [
    "Exact Stage 17 evidence-class thresholds.",
    "Exact Stage 20.1 corridor-density correction formula.",
    "Exact Stage 21 context thresholds and full exclusion schedule.",
    "Exact Stage 22 pairing criteria and balanced-night threshold.",
    "Exact Stage 23A.3 Tier A/B/C threshold values.",
    "Exact Stage 23A.4 pressure-index component weights.",
    "Exact Stage 23A.4 sustained-pressure rule.",
    "Complete upstream SCATS ingestion and cleaning specification.",
    "Exact construction of the older combined freight-exposure score."
  ]
}