Thai Open Transit

An open, structured, versioned and time-aware dataset of Thailand's rail transit network, starting with Bangkok and its metropolitan region (Nonthaburi, Samut Prakan, Pathum Thani).

Live map (beta): thaiopentransit.vercel.app

Nobody in Thailand publishes the rail network as a structured, versioned, temporally-aware open dataset. The map is how we prove the dataset is good.

The dataset is the product. The web map in apps/web is a reference implementation. If a change helps the map but hurts the dataset, the dataset wins.

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What you get

The dataset

Entity	Count	Source of truth
Lines	10	data/source/lines/*.json
Stations	192	data/source/stations/*.json
Segments	187	data/source/segments/*.json

Lines: Airport Rail Link, BTS Sukhumvit, BTS Silom, BTS Gold, MRT Blue, MRT Purple, MRT Pink, MRT Yellow, SRT Dark Red, SRT Light Red.

What makes it different from a list of stations:

• Time-aware. Every station and segment carries valid_from / valid_to and a milestones[] history (construction_started, trial_run, opened, extended, renamed, recoded, suspended, closed). You can ask what the network looked like in any year.
• Status is derived, never edited. A station's status comes from its milestones, so it cannot drift out of sync with its history.
• Stable IDs. A station ID never changes, even when the operator renumbers its code. Old codes live in code_history[].
• Provenance on every fact. Every entity carries source_refs. Data without a source fails validation.
• Bilingual. name_th and name_en on every user-facing entity.

Downloads

Generated by bun run data:build and offered on the site's /download page.

File	Contents
network.json	Current-state lines, stations, segments (no history)
network.geojson	Station points and segment lines for GIS tools
stations.csv	Flat station table for spreadsheets

The web map

A static Next.js site on MapLibre GL with a self-hosted Protomaps basemap (no third-party tile host).

• Lines styled by status: open, under construction, planned, suspended
• Station search in Thai, English, station ID and historical codes
• Station panel with names, lines, structure, accessibility, opened date and last verified date, plus a deep link (?station=BL15)
• Line groups with show / hide, station labels toggle, light and dark themes
• Year slider to watch the network grow over time
• My location and nearest open station (location never leaves the browser)
• English / Thai UI switch
• "Report an error" button that opens a prefilled GitHub issue

The full, current feature list lives in docs/FEATURES.md.

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Build it locally

Requires Bun. No environment variables are needed: cloning and building works offline against the data committed in data/source/.

bun install          # install workspace dependencies
bun run data:build   # generate data/dist/ artifacts from data/source/
cd apps/web && bun run dev

bun run data:build must run before bun run dev: the site reads data/dist/network.json and network.geojson, which are generated, not committed. (apps/web's build script runs data:build for you.)

Commands

Command	What it does
bun run lint	Prettier check
bun run typecheck	TypeScript across packages, apps and scripts
bun run test	Vitest
bun run data:import	Fetch raw OSM data into data/source/
bun run data:seed	Run the historical era seeds in dependency order
bun run data:build	Generate data/dist/ artifacts
bun run data:validate	Schema, graph integrity, provenance, verified dates and budgets
cd apps/web && bun run build	Static export to apps/web/out/

data:validate fails on an empty network by design. To test against an empty data/source/, run ALLOW_EMPTY=1 bun run data:validate.

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How it works

data/source/ + data/overrides/          (structured JSON, reviewed via PR)
        |
        v
scripts/build   -- validated against packages/schema
        |
        v
data/dist/  network.json, network.geojson, stations.csv
        |
        v
apps/web  -- static export  -->  CDN

The public site never talks to a database. It survives outages, costs near zero to host, and stays portable to any static host. The single exception is an optional view counter in an isolated stats store (ADR 0002); the map works without it.

This is the beginning of the README. Read the rest at the original. Read the full README ↗