---
title: "Chokepoint Methodology"
description: "How World Monitor calibrates live flow estimates for the seven global oil & gas shipping chokepoints (Hormuz, Malacca, Suez, Bab el-Mandeb, Turkish Straits, Danish Straits, Panama)."
---

## What we track

Seven oil & gas shipping chokepoints:

| Chokepoint        | Baseline flow (mb/d) |
|-------------------|----------------------|
| Strait of Hormuz  | 21.0 |
| Strait of Malacca | 17.2 |
| Suez Canal / SUMED| 7.6  |
| Bab el-Mandeb     | 6.2  |
| Danish Straits    | 3.0  |
| Turkish Straits   | 2.9  |
| Panama Canal      | 0.9  |

Baselines are EIA's 2023 World Oil Transit Chokepoints publication. Two chokepoints (Turkish + Danish Straits) are **not** covered by common competitor sites — they show up here.

## How live flow is derived

Not an editorial estimate. Every published flow number is calibrated from real observations on a 6-hour refresh:

1. **Portwatch DWT** — IMF / World Bank vessel-tracking aggregation produces per-chokepoint deadweight tonnage by vessel class.
2. **AIS-relay hazard matching** — our AIS ingestion (Railway relay) tags vessels within 500 km of a chokepoint with observed disruption signals (GPS jamming, AIS-off, anchorage clusters, Red/Orange GDACS alerts).
3. **Flow estimate** = current DWT ÷ 365-day baseline DWT, expressed as % of baseline.
4. **Confidence band** = function of vessel sample size and disruption-signal density.

Refresh cadence: `energy:chokepoint-flows:v1` (6h Railway cron) + `supply_chain:chokepoints:v4` warm-ping (30 min).

## Status badge derivation

Each chokepoint has a derived public badge: `normal | restricted | disrupted | closed`. The badge is a deterministic function of:

- Flow ratio (current mb/d ÷ baseline)
- Active AIS disruption count within 500 km
- War-risk tier (low / medium / high / extreme)
- Active navigational warnings (NGA)

We do not publish a bare conclusion label ("sanctions-blocked", "closed by Iran", etc.) without the underlying evidence fields visible alongside.

## Every public number carries its grounds

Every chokepoint card exposes its provenance via a standard attribution footer:

- Source type (`ais` for Portwatch + AIS, `regulator` for EIA baselines)
- Sample size (N AIS observations)
- Method (`AIS-DWT calibrated`)
- Confidence band (`high | medium | low`)
- Data freshness (`Xh ago`)

The footer is an `HTMLElement` with `data-attr-source`, `data-attr-n`, `data-attr-confidence` attributes so agents (MCP clients, scrapers, analyst tools) can extract the same provenance the eye can read.

## Known limits

- AIS signal drops over heavily-jammed regions (Bab el-Mandeb, Hormuz). Gaps are surfaced as reduced confidence, not synthesized away.
- Baselines are annual averages. Seasonal swings (e.g. Suez winter/summer) aren't modeled yet.
- No per-commodity breakdown (crude vs products vs LNG) at the strip level. Coming in a later release via the pipeline registry crosslink.

## Corrections

Every badge transition writes to the public revision log at
[`/corrections`](/corrections). If you spot a wrong number, open a GitHub issue
or email the address listed in the footer — we update on the next classifier
pass.
