GTFS-RT Browser

Browse and inspect GTFS-Realtime TripUpdate messages on an interactive timeline. Search and filter trips by agency, route, relationship, and stop; compare updates with GTFS static schedules, inspect stop times and delays, and open related OJP requests. The app decodes large protobuf feeds in a worker to keep the UI responsive.

Run

npm install
npm start

URL parameters

Parameter	Purpose
agency	Select an agency after the feed loads. Accepts either a business-organisation SBOID (for example, ch:1:sboid:100001) or a GTFS-static agency_id. Exact matches are checked in that order among agencies present in the loaded feed. If neither matches, no agency is selected. Changing the agency dropdown writes the GTFS agency_id to the URL.
q	Search the loaded messages by trip, route, vehicle, agency, SBOID, or stop ID. This does not select the agency dropdown. Editing the search box updates this parameter.
active	Enable Active trips at startup with yes, 1, or true (case-insensitive). The checkbox writes active=yes when enabled and removes the parameter when disabled.
route_type	Filter by a numeric GTFS route type, such as 101. The parameter is absent for All route types and missing route type.
status	Filter by GTFS-RT trip schedule relationship, such as SCHEDULED, ADDED, or CANCELED. The dropdown updates this parameter and removes it for All relationships.

For example, ?agency=ch:1:sboid:100001&active=yes&route_type=101&status=SCHEDULED&q=ch:1:sloid:7000 selects an agency and applies the other filters. The displayed Now time is not a URL parameter; it starts at the OS time and can be changed in the UI.

Architecture

• dto/ contains structured-clone-safe feed data.
• models/ adds derived delay, status, search, and date behavior.
• gtfs-rt-parser.worker.ts decodes protobuf off the UI thread and emits TripUpdate DTOs in batches of 250.