PDX Bus Tracker

Real-time transit tracker for Portland, OR's TriMet system — bus, MAX Light Rail, Streetcar, and WES Commuter Rail — built with Jetpack Compose + Material 3.

PDX Bus Tracker is an unofficial, community-built app. It is not affiliated with, sponsored by, or endorsed by TriMet. "TriMet" and "TransitTracker" are trademarks of the Tri-County Metropolitan Transportation District of Oregon; they are referenced here solely to identify the transit service the app reads data from. TriMet's logos are not used, and all transit data remains the property of TriMet.

Features

• Real-time arrivals — live departure countdowns at any stop, per-run bus positions on a map card, pull-to-refresh, and auto-refresh when the app returns to the foreground
• Trip Planner — plan a from-A-to-B trip right on the map: pick an origin and destination by tapping the map, searching stops, or using your current location; choose depart-now or arrive-by and compare itinerary options whose routes are drawn over the basemap
• Route & stop browser — routes → directions → stops in an animated accordion drill-down
• Nearby stops — find stops around your current GPS location
• Stop search — instant client-side search by name, right on the Home screen
• Favorites & recent stops — saved locally in SQLite; the Favorites pill always lands on the Favorites tab
• Floating pill navigation — a Material 3 Expressive pill bottom bar with a fixed Favorites / Recent / Routes / Trips item set, swipeable screens, and a trailing Settings button (becomes a Back button on Settings)
• Service alerts & detours — active TriMet alerts for the stop and its routes
• Picture-in-picture — mini-window countdown on the arrivals screen (2:3 PiP)
• Dynamic theming — Material 3 with Android 12+ dynamic color; system/light/dark override in Settings
• Route-pinned mode — optional setting to show only the arrivals for the route you opened the stop from
• Wear OS companion — optional watch app mirroring your Favorites & Recent stops (synced automatically over the paired connection) with tap-through to live arrivals on the watch

Screenshots

Real-time arrivals	What's Nearby live map	Search stops	Route & stop browser
Favorites & recent stops	Detour alerts	Free, no ads	Everything in one place

Wear OS companion

Live arrivals	Favorites	Recent stops

Requirements

• Android 12+ (minSdk 31, targetSdk/compileSdk 37)
• JDK 21 (locally and in CI)
• Android SDK platform 37

Architecture

12 Gradle modules — in five app-level modules plus three strictly downward layers (no module→app or feature→feature edges):

Layer	Modules
app	single Activity, Compose Navigation graph, floating pill nav + trailing Settings/Back button, PiP
wear	Wear OS companion — Wear Compose UI mirroring the phone's Favorites/Recent stops with live arrivals; non-standalone, synced from the phone over the Wearable Data Layer
feature/*	home, stops, trips, arrivals, settings — one screen area per module
component/*	transit (TriMet API client: OkHttp + JSON/XML parsing, including the Trip Planner web service), localdata (SQLite favorites/recent stops)
common/*	model (domain models), utils (connectivity, date helpers), ui (theme, shared Compose components, cross-screen state)

No ViewModels, no DI framework, no Room — screens own state with remember { mutableStateOf(...) } and call suspend API functions.

Building

1. Prerequisites: JDK 21 and Android SDK platform 37.
2. Get an API key: register for a free key at developer.trimet.org (required only for real live data; an empty key builds fine).
3. Set the key (either works):

   export TRIMET_API_KEY=your_key_here
   # or
   ./gradlew assembleDebug -PTRIMET_API_KEY=your_key_here

4. Build the debug APK:

   ./gradlew assembleDebug

5. APK location: app/build/outputs/apk/debug/
6. Build the Wear OS companion: ./gradlew :wear:assembleDebug (a renamed PdxBusTracker-wear-debug-1.0.0.apk lands in wear/build/outputs/renamed_apks/debug/). The companion is a build preview — not yet distributed on the Play Store.
7. Run the checks (exactly what CI runs):

   ./gradlew clean test lint assembleDebug --stacktrace

Release builds

Release builds are signed with a local keystore (app/release.keystore, gitignored). Provide the credentials via environment variables — the build fails fast if they are missing:

export STORE_PASSWORD=... KEY_ALIAS=... KEY_PASSWORD=...
./gradlew assembleRelease bundleRelease

• Signed APK: app/build/outputs/apk/release/ (a copy named PdxBusTracker-release-<version>.apk lands in app/build/outputs/renamed_apks/release/)
• Android App Bundle (Google Play): app/build/outputs/bundle/release/app-release.aab — this is what Play Console accepts for uploads

For a local smoke test without real credentials you can build with a debug fallback keystore: -PreleaseSigningFallback=true. Never upload that build.

Tech stack

Stack	Version
Gradle / AGP	9.7.1 / 9.3.1
Kotlin / Compose compiler plugin	2.4.10
Jetpack Compose	BOM 2026.08.00 (Material 3 1.4.0, Navigation 2.9.8)
OkHttp	5.5.0
Joda-Time (android.joda)	2.14.2.1
Kotlin coroutines	1.11.0
MapLibre GL Native (OpenGL backend)	13.6.0 + OpenFreeMap tiles
Wear Compose / androidx.wear	1.6.2 / 1.4.0
Google Play services (wearable)	20.0.1

Privacy Policy

PDX Bus Tracker collects no accounts, no analytics, and no advertising data. Location is used on-device and, when you browse nearby stops or plan a trip from your current location, sent as coordinates to TriMet's public API to look up stops and routes near you. Full details: Privacy Policy.

License

This project is licensed under the MIT License — see the LICENSE file for details.

Third-party libraries are distributed under their own licenses; see THIRD-PARTY-NOTICES.md for the full list and license texts. Basemap tiles are provided by OpenFreeMap (OpenStreetMap data), with attribution shown in-app.

The launcher icon's background is aerial imagery of Portland from the USGS National Map (U.S. Geological Survey — public domain); the route-line artwork on top is original.

The app uses TriMet's public Web Services API (developer.trimet.org). TriMet data remains the property of TriMet. PDX Bus Tracker is an unofficial project — TriMet does not sponsor, endorse, or maintain it.