Board packet · transit data quality · checked 2026-08-01
Big Blue Bus
Grade F · 52.0 / 100
Unchanged since 2026-07-31.
What this grade measures
The quality of the schedule data this agency publishes for trip-planning apps: whether riders using Google Maps, Apple Maps, or Transit see current, correct, and complete information. It measures the data feed, not service quality or operations.
Progress this period
No newly cleared items this period. The score and trend above reflect where the feed stands today.
What needs attention next
Three improvements, in priority order, each sized so the board can see what it is approving:
Ask your AVL vendor why the feed stopped advancing; the GTFS-Realtime header timestamp should move forward on every publish.
The realtime feed's last update was about 478 days old when sampled. A realtime feed this far behind has effectively stopped. Riders see buses that already left, or apps quietly fall back to the schedule while still showing a live label.
Estimated effort: A vendor support ticket; treat it as a feed outage.
Review the rule documentation for 'duplicate_key' at https://gtfs-validator.mobilitydata.org/rules.html and check the flagged rows in your feed.
Duplicate key (flagged by the MobilityData validator). See the linked rule for what this affects.
Estimated effort: Varies.
Check with your AVL vendor that every vehicle assignment flows into TripUpdates, including school-day and tripper runs.
32 of 32 trips scheduled during the sampling window had no live predictions. Riders on those trips get schedule data dressed up as realtime. Caltrans expects every operating trip in TripUpdates.
Estimated effort: A vendor data-mapping question.
Finding handoff
Move one finding to a recheck
Select one finding. Copy the request, make the change in the feed-producing tool, then compare the next complete run.
- Feed evidence
- The realtime feed's last update was about 478 days old when sampled.
- Next action
- Ask your AVL vendor why the feed stopped advancing; the GTFS-Realtime header timestamp should move forward on every publish.
- Recheck
- Publish the changed feed at the same URL. On the next complete, comparable scorecard run, confirm that this finding is no longer reported.
Copy handoff text
- Feed evidence
- Duplicate key (flagged by the MobilityData validator).
- Next action
- Review the rule documentation for 'duplicate_key' at https://gtfs-validator.mobilitydata.org/rules.html and check the flagged rows in your feed.
- Recheck
- Publish the changed feed at the same URL. On the next complete, comparable scorecard run, confirm that this finding is no longer reported.
Copy handoff text
- Feed evidence
- 32 of 32 trips scheduled during the sampling window had no live predictions.
- Next action
- Check with your AVL vendor that every vehicle assignment flows into TripUpdates, including school-day and tripper runs.
- Recheck
- Publish the changed feed at the same URL. On the next complete, comparable scorecard run, confirm that this finding is no longer reported.
Copy handoff text
Produced by the GTFS Scorecard, an open-source data quality tool. A data-quality read to support the board conversation, not an official compliance determination. Live scorecard: https://gtfsscorecard.org/agency/big-blue-bus/. Rubric v1.3, validator 8.0.1.