Bus Tracker

Real-time bus tracking for the Region of Waterloo GRT feeds. This repo includes a FastAPI backend that normalizes GTFS data and a React + Vite frontend that renders live vehicle positions on a map.

Highlights

• FastAPI backend pulls GTFS‑realtime vehicle positions, caches them in memory, and serves a JSON API.
• Static GTFS parsing provides route metadata (names, colors) and optional shapes for polylines.
• React frontend with Leaflet map markers, MUI UI, and React Query polling.
• Route panel shows vehicle counts by route and a quick overview.

Tech stack

• Backend: FastAPI, HTTPX, GTFS‑realtime protobuf bindings
• Frontend: React + Vite + TypeScript, Leaflet + React‑Leaflet, MUI, React Query, Tailwind

Repository layout

.
├─ backend/   # FastAPI service + GTFS parsing
├─ frontend/  # React app (Vite + TypeScript)
└─ README.md

Quick start

1) Backend

From backend/:

1. Create and activate a virtual environment.
2. Install dependencies:
   • pip install -r requirements.txt
3. Create backend/.env (see the root .env.example for a template).
4. Run the API:
   • uvicorn app.main:app --reload --host 0.0.0.0 --port 8000 --env-file .env

2) Frontend

From frontend/:

1. Install dependencies:
   • npm install
2. Create frontend/.env (see the root .env.example for a template).
3. Run the dev server:
   • npm run dev

Environment variables (backend)

Required:

• GRT_VEHICLE_POSITIONS_URL — GTFS‑realtime vehicle positions feed URL.
• GRT_GTFS_STATIC_URL — GTFS static zip URL.

Optional:

• GRT_TRIP_UPDATES_URL — trip updates feed URL (required for arrival predictions).
• GRT_ALERTS_URL — alerts feed URL (not used yet).
• REFRESH_SECONDS — refresh interval in seconds (default: 30).
• GRT_ALLOW_WEAK_TLS — allow weak TLS parameters for feeds (use only if required).

API endpoints

• GET /health
• GET /api/vehicles
• GET /api/vehicles/{vehicle_id}
• GET /api/vehicles/{vehicle_id}/arrivals
• GET /api/routes

Frontend behavior

• Polls /api/vehicles every 10 seconds and /api/routes every 60 seconds.
• Renders vehicles as colored route markers on an OpenStreetMap tile layer.
• Clicking a marker highlights the selected route and draws its GTFS shape (when available).

For container deployments, the frontend Nginx proxy target is runtime-configurable via NGINX_API_UPSTREAM (default backend:80).