Methodology

The accountability rule

Every figure shown in the survey is one of four kinds, marked by its citation chip:

• reported — taken verbatim from the cited source.
• calculated — derived by the exact formula shown beside the figure; every parameter is itself sourced.
• assumed — a stated assumption (for example, converting an official "second half of 2026" window into the tracked date 31 December 2026). The assumption is always written next to the figure.
• traced — geometry drawn through officially reported localities where no surveyed alignment exists yet; rendered as faint pencil and never presented as exact.

No figure in the survey uses a range or an approximation mark. Where sources conflict, one value is chosen and the conflict is recorded in the figure's note.

Annual economic benefit (USD)

Geometry

Operational and under-construction alignments and station coordinates come from the OpenStreetMap survey via the Overpass API (ODbL 1.0), fetched by the data pipeline. Planned lines without OSM geometry are traced through their officially reported anchor localities (geocoded via Nominatim) and drawn as indicative pencil lines.

Update cadence

All figures are re-checked against their sources monthly, and sooner when a line opens. Site changes are recorded, with dates, in the Log of Changes.