Transit Data Health Alerts

Swiftly Transit Data Health Alerts

Swiftly helps agencies keep transit data accurate and reliable by monitoring for common issues and sending out Transit Data Health Alerts. These alerts highlight problems that could affect real-time information in Swiftly as well as rider-facing apps like Google Maps, Transit, and others.

Below are the alerts currently available, what they mean, and who should receive them.

Receiving Transit Data Health Alerts

If you would like to start receiving any of the alerts listed below, please contact your Swiftly Account Manager or Swiftly Technical Support. 

🚍 Vehicle Assignment Issues

What this alert means
Swiftly assigns each vehicle in service to a scheduled trip. A Vehicle Assignment Issue alert is triggered when Swiftly cannot match a significant number of vehicles to scheduled service for an extended period of time.

Possible causes

• Problems with real-time vehicle location feeds (GPS/AVL data), which tell Swiftly where vehicles are.
• Problems with schedule data (GTFS), the static data that describe when and where service should run.
• Mismatches between the two datasets or other data issues.

Why it matters
Stable vehicle assignments can be a proxy for overall transit data health. If vehicles can’t be matched to trips, downstream applications like Swiftly, Google Maps, and the Transit App may not be able to provide accurate information to riders.

Who should get this alert
We recommend this alert for all agencies, especially for IT or maintenance staff who can investigate and resolve data feed issues.

📅 GTFS Expirations

What this alert means
GTFS (General Transit Feed Specification) is the industry-standard format for publishing transit schedules. A GTFS Expiration alert is triggered when the active GTFS file in Swiftly is about to expire or has already expired. A file is considered “expired” when the last service date has passed and no future service is scheduled.

Why it matters
GTFS is the source of truth for downstream applications like Swiftly, Google Maps, and the Transit app. If it expires, they may be sharing incorrect or outdated service information to riders.

Who should get this alert
Anyone responsible for publishing and maintaining GTFS data, such as planners, schedulers, or IT staff.

⚠️ GTFS "Non-Fatal" Processing Issues

What this alert means
This alert triggers when a new GTFS file is uploaded to Swiftly, but contains one or more non-fatal issues.

Why it matters
Correcting these issues ensures that downstream tools (Swiftly, Google Maps, etc.) have accurate schedule data, in turn ensuring riders have the right information about your service.

Who should get this alert
Agency staff responsible for scheduling and maintaining GTFS.

Common Non-Fatal Issues:

• "Stop to Shape Distance Too High": One or more stops on a given shape are too far from the shape path. These issues typically occur when GTFS contains incomplete shapes, when shapes are not accurate to routes, or when stops are not correctly located. 
   
• "Stops Out of Order On Shape": A trip shape cannot be drawn with the provided stop sequence. This usually means the sequence of stops is incorrect or the shape itself has some underlying issues that lead to backtracking when attempting to create a trip/route path.
   
• "Significant drop in percentage of trips with block ids": There are fewer trips with block IDs than expected. Swiftly calculates this by comparing a given file against other recent GTFS processing events.
   
• "Not all supplied block translations were found in trips.txt": If your agency uses block translations to modify the block IDs in your GTFS file, this error indicates that the translation file may need to be corrected and that some blocks may not be getting translated. This can lead to unfamiliar block IDs appearing in the Swiftly platform and vehicle assignment issues.
   
• "There are multiple route_ids that have the same short_name in routes.txt": Swiftly uses short_names to uniquely identify routes. In cases where multiple routes share the same short name, their data will be merged in Swiftly (i.e. selecting the given route short name will show information for all route_ids that share the name in dashboard products like Live Ops, GPS Playback, etc.). If you would prefer each route be treated separately by the platform, please add unique short_names.
   
• "Trips in trips.txt have no shape_id. We will create a simple trip shape connecting consecutive stops": One or more trips have been provided without a shape. Because Swiftly has no way of inferring the shape of the route, straight lines will connect stops. This can have major impacts on real-time and historical data quality if not corrected. This issue also means other downstream consumers (like rider apps) have no agency-created shape information to display to riders.
   
• "Encountered the same stop_id twice in a row": Within the "stop_times.txt" file, we encountered the same stop_id multiple times in a row. If the stop_times appear to be identical, we will simply ignore the second one. If there are differences (such as differing arrival times), we will merge them into a single stop_time.
   
• "Small Amount of Service": The first service date of the file has less service than expected. This is calculated by comparing the number of trips on the first service date to the average number of trips on the same day of the week in past GTFS files.

🛑 GTFS “Fatal Processing” Issues

What this alert means
This alert is triggered when a new GTFS file is uploaded to Swiftly but cannot be processed or activated due to critical errors.

Why this happens

• The GTFS file is corrupted or cannot be opened.
• The file contains errors that conflict with the GTFS specification in a major way.
• Activating the file would cause critical issues in the Swiftly platform.

Why it matters
When a GTFS file cannot be processed, Swiftly cannot use it as the active schedule. This can disrupt downstream data quality until a corrected file is uploaded.

Who should get this alert
Staff responsible for GTFS data publishing and validation (typically schedulers, planners, or IT).