Real-time traffic flow from the HERE 'Traffic' API in areas of interest (AOIs). The traffic flow data contains speed ("SP") and congestion (jam factor: "JF") information, which corresponds to the status of the traffic at the time of the query.

flow(aoi, min_jam_factor = 0, url_only = FALSE)



sf object, Areas of Interest (POIs) of geometry type POLYGON.


numeric, only retrieve flow information with a jam factor greater than the value provided (default = 0).


boolean, only return the generated URLs (default = FALSE)?


An sf object containing the requested traffic flow information.


The maximum width and height of the bounding box of the input AOIs is 10 degrees. This means that each polygon (= one row) in the AOI sf object should fit in a 10 x 10 degree bbox.

Explanation of the traffic flow variables:

  • "PC": Point TMC location code.

  • "DE": Text description of the road.

  • "QD": Queuing direction. '+' or '-'. Note this is the opposite of the travel direction in the fully qualified ID, For example for location 107+03021 the QD would be '-'.

  • "LE": Length of the stretch of road.

  • "TY": Type information for the given Location Referencing container. This may be a freely defined string.

  • "SP": Speed (based on UNITS) capped by speed limit.

  • "FF": The free flow speed on this stretch of the road.

  • "JF": The number between 0.0 and 10.0 indicating the expected quality of travel. When there is a road closure, the Jam Factor will be 10. As the number approaches 10.0 the quality of travel is getting worse. -1.0 indicates that a Jam Factor could not be calculated.

  • "CN": Confidence, an indication of how the speed was determined. -1.0 road closed. 1.0=100%.


# Provide an API Key for a HERE project
set_key("<YOUR API KEY>")

# Real-time traffic flow
flow <- flow(
  aoi = aoi[aoi$code == "LI", ],
  url_only = TRUE