missing_level_id: GTFS validation rule (levels.txt) Error
A pathway or stop references a level_id that is absent from levels.txt.
What the rule checks
A pathway or stop references a level_id that is absent from levels.txt.
Severity: error
An error marks data that breaks the GTFS specification. A journey planner or a rider app may refuse the file, or show a wrong version of it. Correct it before publishing the GTFS.
Where it applies
The rule applies to levels.txt. This file describes the levels of a station.
Finding and correcting it
Open the GTFS in GTFS Express. Reading is free, and the validation, by the MobilityData validator and the rules of GTFS Express itself, lists the occurrences of missing_level_id with the file and rows involved. The correction is made in a draft, by hand or from a brief, with the licence: the corrected GTFS is validated again before it is delivered, and the change can be undone.
In the MobilityData validator
The MobilityData GTFS validator uses the same code, missing_level_id. Its documentation describes each rule: MobilityData validator rules.