{
  "slug": "tt009.gateway.waiting-rate",
  "name": "Average waiting rate by gateway",
  "unit": "ratio",
  "horizon": "medium",
  "grade": "observed",
  "grade_means": "We watched it happen: our own AIS receivers (via the aisstream.io terrestrial network), our timestamps, our archive.",
  "description": "Sum of waiting hours divided by sum of hours alongside berth — UNCTAD (1983), codified as World Bank Transport PS-6 (Chung, 1993) indicator 6. Design range 0.05-0.20, PIANC about 0.165. An aggregate ratio, never an average of ratios.",
  "instrument": {
    "id": "TT-009",
    "name": "Berth queueing",
    "clock": "fast",
    "role": "reporter",
    "source": "Own AIS receivers, via the TT-001 archive",
    "source_url": "https://ais.trimtabist.com/gateways"
  },
  "coverage": {
    "from": "2026-07-26",
    "to": null
  },
  "publishable_ranges": [],
  "status": "suspended",
  "withdrawn": {
    "since": "1970-01-01",
    "until": null,
    "reason": "THREE OPEN BLOCKERS. (1) Right-censoring deletes the longest waits and the bias grows with congestion. (2) Not reconciled against the World Bank CPPI annex, whose published berth-share converts arithmetically to this same rate. (3) The fleet-mix check is unrun: waiting falls with ship size while service time rises, so this could measure fleet composition rather than port performance. See berthing/PHASES.md.",
    "finding": null
  },
  "citation": "Trimtabist TT-009 Berth queueing, own AIS receivers, 10 US container gateways. Method: berthing/METHOD.md. Grade: observed.",
  "citationShort": "Trimtab TT-009 Berth queueing, \"Average waiting rate by gateway\" (retrieved 2026-08-06).",
  "licence": "CC BY 4.0",
  "retrieved_at": "2026-08-06T13:44:59.246Z",
  "urls": {
    "page": "https://trimtabist.com/series/tt009.gateway.waiting-rate",
    "csv": "https://trimtabist.com/series/tt009.gateway.waiting-rate.csv",
    "metadata": "https://trimtabist.com/series/tt009.gateway.waiting-rate.metadata.json"
  }
}