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:
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
numeric, only retrieve flow information with a jam factor greater than the value provided (
default = 0).
boolean, only return the generated URLs (
default = FALSE)?
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 )