fix_gtfs: Fix common problems in GTFS feeds

In gtfstools: General Transit Feed Specification (GTFS) Editing and Analysing Tools

Fix common problems in GTFS feeds

Description

Cleans a GTFS feed in one call, by removing duplicated entries and unused ids, optionally capping the speed of trips, filling blank stop times, optionally setting a minimum dwell time at intermediate stops and recalculating the distances travelled along shapes (replacing any existing ones).

Usage

fix_gtfs(
  gtfs,
  max_speed = NULL,
  speed_unit = "km/h",
  min_dwell_time = NULL,
  dwell_time_unit = "s"
)

Arguments

gtfs	A GTFS object, as created by read_gtfs().
max_speed	A number. The maximum speed of trips, in the unit given by speed_unit. If NULL (the default), speeds are not capped.
speed_unit	A string representing the unit in which max_speed is given. One of "km/h" (the default), "m/s" or "mph" (miles per hour).
min_dwell_time	A non-negative number. The minimum time vehicles remain stopped at each intermediate stop of their trips, with their doors open to serve passengers, in the unit given by dwell_time_unit. If NULL (the default), dwell times are not changed.
dwell_time_unit	A string representing the time unit in which min_dwell_time is given. One of "s" (seconds, the default), "min" (minutes), "h" (hours) or "d" (days).

Value

The fixed GTFS object.

Details

The feed goes through the following steps, in this order:

1. remove_duplicates() removes duplicated entries from every table;

2. remove_unused_ids() removes the trips without stop_times, and the entries of every table that no remaining trip uses (see its documentation for the exceptions). Note that this removes data from the feed;

3. set_max_speed(), only if max_speed is given, slows down the parts of trips that are faster than max_speed. Only spans between stops with known times are capped, and spans that end before they start (e.g. times after midnight written as "00:30:00") are left unchanged, with a warning;

4. interpolate_stop_times() fills blank stop times from the times of the stops around them. Speeds are capped before interpolating, so the filled times follow the capped times. Interpolated times are rounded to the second. Stops whose times can't be interpolated are left blank, with a warning;

5. set_min_dwell_time(), only if min_dwell_time is given, delays the departure from each intermediate stop whose dwell time is shorter than min_dwell_time, so that vehicles stay there for at least that long. The minimum is rounded to the second. The later times of each changed trip are shifted accordingly, so the trip ends later (for trips listed in frequencies, every departure gets longer). This is done after filling blank times, so the filled stops also get the minimum. Only the stops between the first and the last stop with times of each trip get the minimum, so trips keep their start times. Stops with negative dwell times (departures earlier than arrivals) also get it, see set_min_dwell_time() for times after midnight written as "00:30:00";

6. interpolate_shape_dist_traveled(), only if the feed has a shapes table and trips has a shape_id column, replaces the shape_dist_traveled columns of stop_times and shapes with the distances, in meters, from the start of each shape. Existing values, whatever their unit, are replaced, and stops that can't be located along their trip's shape get NA.

The trips and stop_times tables are always required, and stops is required to cap speeds, to fill blank times and to calculate the distances travelled along shapes. The warnings raised are those of the functions above, so some warnings (e.g. about trips not linked to a shape) may be raised more than once.

See Also

remove_duplicates(), remove_unused_ids(), set_max_speed(), interpolate_stop_times(), set_min_dwell_time(), interpolate_shape_dist_traveled()

Examples

library(dplyr)

data_path <- system.file("extdata/spo_gtfs.zip", package = "gtfstools")

gtfs <- read_gtfs(data_path)

fixed_gtfs <- fix_gtfs(gtfs, max_speed = 40, min_dwell_time = 30)

# duplicated agencies were removed, and the trip is now slower and stays at
# least 30 seconds at each intermediate stop
gtfs$agency
fixed_gtfs$agency

gtfs$stop_times |>
  filter(trip_id == "CPTM L07-0") |>
  slice_tail(n = 1)

fixed_gtfs$stop_times |>
  filter(trip_id == "CPTM L07-0") |>
  slice_tail(n = 1)

gtfstools documentation built on Oct. 28, 2026, 5:13 p.m.