a2transit

Ann Arbor is served by two bus networks that ignore each other: TheRide, the city system, and U-M MBus, the university shuttles. Neither agency's trip planner will route you onto the other's buses, even where their stops share a corner. 728 of their stop pairs are within a 400 m walk, and some are under two metres apart. a2transit loads both feeds into one routing graph, so a single search plans across both, walks you between them, and adjusts for the buses that are actually running late.

▶ Try it live · API docs

_{Blake Transit Center → Pierpont Commons. Two options: 65 minutes on one TheRide bus, or 32 minutes changing onto MBus halfway. 112 buses live.}

The live demo sleeps when idle, so the first request can take a minute to wake the API. It shows its progress while it does.

Stack

Backend: Python 3.12, FastAPI, SQLAlchemy, PostgreSQL + PostGIS, Redis, GTFS-Realtime Frontend: TypeScript, React, Vite, MapLibre GL JS, OpenFreeMap

Features

• Plan a trip across TheRide and MBus in one search, the first planner that routes between the two networks.
• Search by stop name or street address; both are looked up at once, so you can type either.
• Door to door: start and end anywhere, not just at a bus stop. Click the map to drop a point.
• Live vehicle positions on the map, with delays folded into the plan. A late bus changes which one you are told to catch, not just the time printed beside it.
• Every sensible option, not just the fastest: fewest changes first, fastest last, with walking time and transfers shown per option.
• Departure boards for any stop in the itinerary.
• Shareable trip links: the whole trip lives in the URL.
• Service alerts filtered to the routes you are actually using.

Docs

Routing · Architecture · HTTP API · Running it locally · Deployment · Measurements · Feed provenance

Licence and data

The code is MIT (see LICENSE). The transit data is not, and the two are kept separate on purpose: no feed data is redistributed in this repository, data/ is git-ignored, and TheRide's licence is explicitly nontransferable. Full terms in docs/licences.md.

TheRide requires this notice wherever their data appears. It is in the footer of every screen and in the body of every /plan response:

Transit scheduling, geographic, and real-time data provided by permission of AAATA/TheRide.

Campus transit data from University of Michigan Transit Services. Map tiles © OpenFreeMap and © OpenMapTiles, from OpenStreetMap data © OpenStreetMap contributors.