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)

Arguments

aoi

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

min_jam_factor

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

url_only

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

Value

An sf object containing the requested traffic flow information.

Note

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%.

References

Examples

# 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 )