Get trip speed

Source: R/get_trip_speed.R

Returns the speed of each specified trip_id, based on the geometry created from either the shapes or the stop_times file (or both).

get_trip_speed(
  gtfs,
  trip_id = NULL,
  file = "shapes",
  unit = "km/h",
  sort_sequence = FALSE
)

Arguments

gtfs

A GTFS object, as created by read_gtfs().

trip_id

A character vector including the trip_ids to have their speeds calculated. If NULL (the default), the function calculates the speed of every trip_id in the GTFS.

file

The file from which geometries should be generated, either shapes or stop_times (geometries are used to calculate the length of a trip). Defaults to shapes.

unit

A string representing the unit in which the speeds are desired. Either "km/h" (the default) or "m/s".

sort_sequence

Ultimately passed to get_trip_length(), a logical specifying whether to sort shapes and timetables by shape_pt_sequence and stop_sequence, respectively. Speeds calculated from trip trajectories generated with unordered sequences do not correctly depict the actual trip speeds. Defaults to FALSE, otherwise spec-compliant feeds, in which shape/timetables points are already ordered by shape_pt_sequence/stop_sequence, would be penalized through longer processing times.

Value

A data.table containing the duration of each specified trip and the file from which geometries were generated.

Details

Please check get_trip_geometry() documentation to understand how geometry generation differs depending on the chosen file.

Examples

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

gtfs <- read_gtfs(data_path)

trip_speed <- get_trip_speed(gtfs)
head(trip_speed)
#>      trip_id origin_file     speed
#> 1: 2002-10-0      shapes  8.952511
#> 2: 2105-10-0      shapes 10.253365
#> 3: 2105-10-1      shapes  9.795292
#> 4: 2161-10-0      shapes 11.182534
#> 5: 2161-10-1      shapes 11.784458
#> 6: 4491-10-0      shapes 13.203560

trip_ids <- c("CPTM L07-0", "2002-10-0")
trip_speed <- get_trip_speed(gtfs, trip_ids)
trip_speed
#>       trip_id origin_file     speed
#> 1:  2002-10-0      shapes  8.952511
#> 2: CPTM L07-0      shapes 26.787768

trip_speed <- get_trip_speed(
  gtfs,
  trip_ids,
  file = c("shapes", "stop_times")
)
trip_speed
#>       trip_id origin_file     speed
#> 1:  2002-10-0      shapes  8.952511
#> 2:  2002-10-0  stop_times  6.559614
#> 3: CPTM L07-0      shapes 26.787768
#> 4: CPTM L07-0  stop_times 24.342591

trip_speed <- get_trip_speed(gtfs, trip_ids, unit = "m/s")
trip_speed
#>       trip_id origin_file    speed
#> 1:  2002-10-0      shapes 2.486809
#> 2: CPTM L07-0      shapes 7.441047