stop_time_with_arrival_before_previous_departure_time: time goes back Error

Within a trip, the arrival time at a stop is earlier than the departure time from the previous stop. Why this GTFS error appears and how to fix the times.

Updated on 21 October 2026

What this rule means

In stop_times.txt, the stop times of a trip are ordered by stop_sequence. A vehicle cannot reach a stop before leaving the previous one: the arrival_time of a stop time must be greater than or equal to the departure_time of the one before it. The rule fires when it is strictly smaller. Stop times without times (untimed intermediate stops) are skipped: the comparison is made with the last stop time that has one.

Severity: error.

Why it matters

A negative running time makes the trip incoherent. Journey planners may offer impossible connections, show times out of order or drop the trip. In the report, this error often comes with other notices on the same trip.

Common causes

Times after midnight written 00:10:00 instead of 24:10:00 on a trip that started the evening before.
A stop_sequence that does not follow the real order of calls, for instance after a stop was inserted.
A typing error on a time (08:15 entered as 07:15).
A trip shifted by hand on only part of its stops.

How to fix it

Look at the whole trip in stop_times.txt, sorted by stop_sequence, and find where the times go backwards. Correct the wrong time, or put stop_sequence back into the real order if the stops are the ones out of place. For a trip that runs past midnight, every time after midnight goes beyond 24.

In GTFS Express, each occurrence in the report names the trip and the stop time. "Fix one by one" opens the stop time in the editor with the field flagged. Each correction is a retouche in the draft, and "Re-validate" confirms the result.

Example

trip_id,arrival_time,departure_time,stop_id,stop_sequence
T2240,23:52:00,23:52:00,S100,1
T2240,23:58:00,23:58:00,S110,2
T2240,00:04:00,00:04:00,S120,3

Fixed:

trip_id,arrival_time,departure_time,stop_id,stop_sequence
T2240,23:52:00,23:52:00,S100,1
T2240,23:58:00,23:58:00,S110,2
T2240,24:04:00,24:04:00,S120,3