# Atlanta Transit Alerts

> An unofficial public archive of MARTA train, streetcar, and bus service alerts plus bot-detected disruptions. Not affiliated with MARTA.

Each incident pairs an official alert with bot observations (gap, bunching, ghost vehicle, cold platform/segment, and related detections) into a single object, merged server-side. The same data the site renders is published at stable URLs as JSON, CSV, and feeds, with no auth. Every incident has a `kind` of `train` or `bus`. Train routes use line names such as `red`, `gold`, `blue`, `green`, and `streetcar`; bus routes use MARTA route ids. Timestamps are epoch milliseconds in JSON and ISO 8601 UTC in CSV.

## Data API
- [Recent incidents (JSON)](https://data.atlantatransitalerts.app/alerts-recent.json): Bounded recent window — every incident that is active (any age) or first seen in the last 93 days. Top-level `incidents[]`, one object per real-world disruption; `official` is the legacy field name for the official alert block, and `observations[]` are bot detections. Poll this for current data.
- [Data index (JSON)](https://data.atlantatransitalerts.app/alerts-index.json): Manifest of the archive — `months[]` (monthly shards at `alerts/<YYYY-MM>.json`, by America/New_York month of `first_seen`), `lines[]` (per-line all-time files at `incidents/by-line/<lineKey>.json`), plus `id_month`/`rkey_month`. Union every month shard for the full history.
- [Aggregates (JSON)](https://data.atlantatransitalerts.app/aggregates.json): Precomputed year-over-year counts (`yoy.overall` + `by_mode.{train,bus}`).
- [Incidents (JSON, deprecated)](https://data.atlantatransitalerts.app/alerts.json): Full-history archive, same `incidents[]` shape. Still published but deprecated and will be retired — migrate to the recent + index files above.
- [Accessibility outages (JSON)](https://data.atlantatransitalerts.app/accessibility.json): Elevator/escalator outage archive. Top-level `outages[]`, one object per unit outage.
- [Daily counts (JSON)](https://data.atlantatransitalerts.app/daily-counts.json): Per-day train/bus incident counts behind the calendar heatmap.
- [Incidents (CSV)](https://data.atlantatransitalerts.app/alerts.csv): Flat mirror, one row per alert or observation, with an explicit `type` column.
- [Data changelog](https://atlantatransitalerts.app/data/CHANGELOG.md): Breaking changes to the data shape.
- [Atom feed](https://atlantatransitalerts.app/feed.xml) and [JSON feed](https://atlantatransitalerts.app/feed.json): Recent incidents. Per-line/route feeds live at `/feed/line/<line>.xml` and `/feed/route/<route>.xml`, each with a JSON-feed twin.
- [API catalog](https://atlantatransitalerts.app/.well-known/api-catalog): Machine-readable index of these endpoints.

## Pages
- [Homepage](https://atlantatransitalerts.app/): Active alerts, line/route filters, daily summary, and the incident feed.
- [Calendar](https://atlantatransitalerts.app/calendar): 12-month daily incident heatmap.
- [This week](https://atlantatransitalerts.app/week): Recap of the current Sun-Sat week.
- [Stats](https://atlantatransitalerts.app/stats): Worst day, worst hour, most-affected station, longest incident, plus year-over-year.
- [Accessibility](https://atlantatransitalerts.app/accessibility): Elevator/escalator status and recent station outage history.
- [Compare](https://atlantatransitalerts.app/compare): Side-by-side reliability for up to 3 lines or routes (`?trains=red,gold` / `?buses=15,110`).
- [Train system health](https://atlantatransitalerts.app/system/trains) and [Bus system health](https://atlantatransitalerts.app/system/buses): Mode-wide dashboards.
- Line pages: `https://atlantatransitalerts.app/line/<line>` (e.g. `/line/red`).
- Route pages: `https://atlantatransitalerts.app/route/<routeId>` (e.g. `/route/15`).
- Station pages: `https://atlantatransitalerts.app/station/<slug>` (kebab-case, e.g. `/station/five-points`).
- [All stations](https://atlantatransitalerts.app/stations): A-Z directory of MARTA rail and streetcar stations.
- [All routes](https://atlantatransitalerts.app/routes): Directory of MARTA train lines and bus routes.
- Day pages: `https://atlantatransitalerts.app/day/<YYYY-MM-DD>`.
- Event pages: `https://atlantatransitalerts.app/event/<id>` (id = Bluesky post rkey; the incident permalink).

## Notes
- Source code and field-by-field documentation: https://github.com/cailinpitt/atlanta-transit-alerts
- Full data schema: [/llms-full.txt](https://atlantatransitalerts.app/llms-full.txt)
- Please cache responses, don't poll faster than every few minutes, and credit the project if you build something public.