# description
A real-time update to the predicted arrival or departure time of a vehicle at a specific stop within a journey.

# properties.arrivalDelay.description
Arrival delay in seconds (negative = early)

# properties.departureDelay.description
Departure delay in seconds (negative = early)

# properties.scheduleRelationship.description
Relationship to schedule (SCHEDULED, SKIPPED, NO_DATA)

# properties.id.description
Unique identifier for the tracking record

# properties.url.description
URL endpoint for real-time tracking information

# properties.validity.description
Validity period for this tracking record