Public Transit API
In hereR: 'sf'-Based Interface to the 'HERE' REST APIs

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
library(hereR)
library(sf)

if (requireNamespace("mapview", quietly = TRUE)) {
  mapview::mapviewOptions(
    fgb = FALSE,
    vector.palette = colorRampPalette(
      c("#000004FF", "#420A68FF", "#932667FF", "#DD513AFF", "#FCA50AFF", "#FCFFA4FF")
    )
  )
}

connection_section <- hereR:::example$connection_section
connection_summary <- hereR:::example$connection_summary
stations <- hereR:::example$station

Request public transport connections between given points and find stations nearby using the 'HERE Public Transit' API.

Connections

The function connection() allows to request public transport connections from the API. Two types of requests are provided:

connection(..., summary = FALSE): The public transport connections are returned as multiple sections with the same vehicle and transport mode. Each row represents a section with a detailed route geometry.
connection(..., summary = TRUE): A summary of the connections is retrieved, where each connection is represented as one row with a unified and simplified geometry.

1. Sections

Request available public transport connections as detailed sections:

connection_section <- connection(
  origin = poi[3:4, ],
  destination = poi[5:6, ],
  summary = FALSE
)

The id column corresponds to the row of the input locations (origin and destination) and the rank column enumerates the alternative routes. The maximum number of alternatives can be set by the results parameter. Each row in the returned sf object corresponds to a route section with a transport mode in a vehicle without a transfer.

knitr::kable(head(as.data.frame(connection_section)[, colnames(connection_section) != "geometry"]), format = "html")

Print the public transport sections on an interactive leaflet map:

if (requireNamespace("mapview", quietly = TRUE)) {
  mapview::mapview(connection_section,
    zcol = "mode",
    layer.name = "Transport mode",
    map.types = c("Esri.WorldTopoMap"),
    homebutton = FALSE
  )
}

2. Summary

Request a summary of the available public transport connections:

connection_summary <- connection(
  origin = poi[3:4, ],
  destination = poi[5:6, ],
  summary = TRUE
)

knitr::kable(head(as.data.frame(connection_summary)[, colnames(connection_summary) != "geometry"]), format = "html")

Stations

The function station() allows to request public transport stations nearby points of interest (POIs). The radius defines the maximum search distance in meters and results specifies the maximum number of returned stations. The returned sf object contains the locations of the stations and the available public transport lines at the station.

stations <- station(
  poi = poi,
  radius = 500,
  results = 5
)

Print the POIs, the radius and stations on an interactive leaflet map:

buffer <-
  poi %>%
  st_transform(2056) %>%
  st_buffer(500) %>%
  st_transform(4326)

if (requireNamespace("mapview", quietly = TRUE)) {
  m <-
    mapview::mapview(poi,
      alpha.region = 1, col.region = "black",
      label = poi$city, layer.name = "POIs",
      map.types = c("Esri.WorldTopoMap"), homebutton = FALSE
    ) +
    mapview::mapview(stations,
      col.region = "yellow", alpha = 1,
      label = stations$station, layer.name = "Stations",
      homebutton = FALSE
    ) +
    mapview::mapview(buffer,
      col.region = "transparent", alpha.region = 0,
      layer.name = "Buffer", homebutton = FALSE, legend = FALSE
    )
  m
}