At least in Puget Sound, every transit operator (except for Community Transit) makes their real-time bus arrival data publicly available for free via Sound Tran

At least in Puget Sound, every transit operator (except for Community Transit) makes their real-time bus arrival data publicly available for free via Sound Transit's Open Transit Data service, OneBusAway: https://www.soundtransit.org/Open-Transit-Data https://www.soundtransit.org/Open-Transit-Data (OneBusAway is the name of the app that shows information to end users and the name of the API service that developers can query.) I know that this service is widely available and free because I've had an API key for years and have (accidentally) pummeled the service with requests and have heard nary a peep from Sound Transit asking me for money.