TfL's open data shows what publishing the feed can do
A Deloitte study for Transport for London valued its free open data at up to £130 million a year for London's economy.
Transport for London publishes its data through a free unified API. According to TfL, more than 600 apps use the data, more than 13,000 developers are registered, and 42 percent of Londoners use an app powered by it; a Deloitte study TfL commissioned valued the benefit to London's economy at up to £130 million a year.
The study dates from 2017, but the model it describes still holds: the agency publishes reliable data, and others build services that riders use.
ESS view: for US agencies, a complete and accurate real-time feed is a precondition for any AI tool, because it gives both third-party apps and internal systems something trustworthy to read.