set_route_frequency: Set route frequency

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

Set route frequency

Description

Sets the headway of each specified route_id within a given time of day, by replacing its trips in that time of day with a single frequency-based trip, described in the frequencies table.

Usage

set_route_frequency(
  gtfs,
  route_id = NULL,
  headway,
  from,
  to,
  route_type = NULL
)

Arguments

gtfs	A GTFS object, as created by read_gtfs().
route_id	A character vector including the route_ids to have their frequency set. route_ids not listed in trips are ignored, with a warning. If NULL (the default), route_type must be given, and the frequency of every route of these types is set.
headway	A number. The headway to be set, in minutes. It is rounded to whole seconds and applies to every route_id (call the function once per route to set different headways).
from	A string. The starting point of the time of day, in the "HH:MM:SS" format.
to	A string. The ending point of the time of day, in the "HH:MM:SS" format. Must be later than from.
route_type	An integer vector of route_types (see filter_by_route_type()). If given, only routes of these types are changed; together with route_id, it restricts the given routes. route_types not listed in routes are ignored. If NULL (the default), routes of any type are changed.

Value

A GTFS object with updated frequencies, trips and stop_times tables (and transfers, when present). If the given GTFS object has no frequencies table, one is created.

Details

Departures are grouped by route_id, service_id and direction_id (if present in trips) and counted within the time of day (at or after from and before to) as in get_route_frequency(), which thus reports the new headway (exactly, when the length of the time of day is a multiple of headway). Departures after midnight are listed with times past "24:00:00", so use a time of day such as "24:00:00"-"26:00:00" for them.

The function changes existing service, it does not create it: groups with no departure within the time of day are not modified, and scheduled trips that depart before from are not changed, even if they run within the time of day. In each other group:

• the trips that depart within the time of day are replaced by a single template: among the trips of the stop pattern (see get_stop_times_patterns()) with the most departures within the time of day, the one that departs first. Its travel times apply to all the new departures. The other trips that depart within the time of day are removed (frequency-based ones instead lose their frequencies entries within the time of day, see below);

• a frequencies entry is added for the template, from from to to, with headway_secs set to headway and exact_times = 0; the transfers entries that refer to the template then apply to all of its departures;

• the existing frequencies entries of the group's trips are cut at from and to, keeping their departures outside the time of day exactly as before (as converted by frequencies_to_stop_times() with strategy = "exact"). Trips left without any departure are removed from trips, stop_times and transfers.

Groups whose trips within the time of day have no departure time in stop_times can't have a template and are left unchanged, with a warning. Removed trips may leave unused entries in other tables, such as shapes and calendar, which remove_unused_ids() removes.

stop_times requires the stop_id and stop_sequence fields. Existing ⁠_secs⁠ columns in frequencies (e.g. created with convert_time_to_seconds()) are updated.

Examples

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

get_route_frequency(
  gtfs,
  route_id = "CPTM L07",
  from = "07:00:00",
  to = "09:00:00"
)

# sets a 10 minutes headway from 7 to 9 am
new_gtfs <- set_route_frequency(
  gtfs,
  route_id = "CPTM L07",
  headway = 10,
  from = "07:00:00",
  to = "09:00:00"
)
get_route_frequency(
  new_gtfs,
  route_id = "CPTM L07",
  from = "07:00:00",
  to = "09:00:00"
)

# use frequencies_to_stop_times() to get the scheduled trips
new_gtfs <- frequencies_to_stop_times(new_gtfs)

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