Did the bus arrive before the bell?

Arrival is the interpolated time a vehicle entered the 250 m school geofence. “First seen inside” is shown with lower confidence when no preceding outside observation was available.

Departure is the interpolated time a vehicle crossed 250 m from its scheduled origin. A trip first seen already outside the origin geofence is labeled uncertain and is not classified as more than 15 minutes late.

Dropped / not observed means the scheduled trip had no usable observation. It describes this independent data record and is not proof that no vehicle operated.

School start is effective-dated. Every daily report preserves the start time and validity period used for that date.