Is your feature request related to a problem? Please describe.

In the transit database, we are tracking "Services". Services are public transport services that one or many organizations provide. Sometimes, a GTFS dataset can have multiple services within it. This is obviously possible with regional feeds, but it can also happen where one transit agency has multiple services (for example SacRT rail and SacRT bus are considered two services that are described in one GTFS dataset). It would be great to be able to analyze these subsets of services in our data pipeline such that it would be possible to analyze the GTFS data associated with a service just like it is possible today to analyze the services described in a whole GTFS dataset today.

Describe the solution you'd like

Stuff that needs to happen to get this working:

• Airtable view: California Transit #973
• Link Airtable data about datasets to GTFS feed data.... or retire agencies.yml in favor of airtable data? #775
• Advanced GTFS assessment of sub-parts of a feed #776
• Validate the quality of airtable data that filters segments of a GTFS feed #1207
• Have ability to filter a GTFS-RT dataset into a service subcomponent

Describe alternatives you've considered

Not doing it at all and just using GTFS datasets like we are today, but we probably should do this.

Additional context

This will help us identify any issues occurring with specific parts of transit agencies. Also, the assessment team would then have an easier time assessing service-based questions.