Potential shift from trip_id to stop path for historical travel times lookup

[rbarcham]

Is your enhancement request to replace an existing functionality within TheTransitClock?
Yes, potential to enhance/replace current understanding of historical travel times on a trip basis.

Is your enhancement request related to a problem? Please describe.
Historical travel times based on trip_id are brittle to changes in trip_id - there are implications not only for inconsistent GTFS, but more importantly for service changes/disruptions.

Describe the solution you'd like
Could potentially replace cache keyed off trip_id with something was route + stop path based; would also need time bucket component.

Describe alternatives you've considered
Various other approaches possible.

Additional context
May require and/or be linked to additional cache performance improvements.

Example datasets
TBD