Pull metro sensor configuration

Source: R/pull_configuration.R

Read MnDOT JSON feed and wrangle into a tidy dataframe containing 20 variables related to sensor configuration. Useful for mapping (contains lat/lons) and calculating performance measures (contains detector_field).

pull_configuration(return_opt = "in_memory", .quiet = TRUE)

Arguments

return_opt

character, indicate how to return the data. "within_dir" will return the data within the directory as a csv entitled "Configuration of Metro Detectors YYYY-MM-DD". "in-memory" will return the data in R, but requires assignment.

.quiet

logical, whether to hide messages. Default is TRUE

Value

dataframe containing 20 variables, including detector_field and lat/lons, for each sensor in MnDOT's metro district

  • detector_name character, the detector's unique identifier in numbers

  • detector_label character, the detector's label including abbreviations of the roads associated with the roadway node.

  • detector_category character, the detector lane type in code. Source

    • "" Mainline

    • "A" Auxiliary, mainline auxiliary (ends within a mile)

    • "B" Bypass, ramp meter bypass

    • "CD" Collector/Distributor

    • "D" Shoulder, mainline shoulder

    • "G" Green, ramp meter displayed green count

    • "H" High-Occupancy Vehicle

    • "HT" High-Occupancy Vehicle or Toll

    • "M" Merge, Freeway on-ramp (counts all merging traffic)

    • "O" Omnibus, bus only

    • "P" Passage, ramp meter passage

    • "PK" Parking, parking space presence detector

    • "Q" Queue, ramp metering queue

    • "R" Reversible mainline

    • "V" Velocity, mainline speed loop

    • "X" Exit, freeway exit ramp

  • detector_lane character, the detector's lane. Lanes are numbered from right-to-left, starting with the right lane as 1.

  • detector_field character, the detector's field length in feet

  • detector_abandoned character, whether the detector is no longer in use.

  • r_node_name character, abbreviated roadway node name.

  • r_node_n_type character, one of "Station", "Exit", "Entrance", or "Intersection"

  • r_node_transition character, how the entrance or exit nodes connect with linked nodes

  • r_node_label character, unique road name, including affixes such as “St” or “Rd” or stall number

  • r_node_lon character, the roadway node longitude

  • r_node_lat character, the roadway node latitude

  • r_node_lanes character, for an entrance or exit ramp, this is the number of lanes entering or exiting the corridor. Otherwise, it is the number of lanes on the corridor.

  • r_node_shift character, the difference (number of lanes) between the corridor reference lane and the attach side of the roadway node.

  • r_node_s_limit character, the posted speed limit in miles per hour

  • r_node_station_id character, A unique identifier for the detectors associated with a station roadway node

  • r_node_attach_side character, whether the r_node is attached to the left side of the road. This can be used to create left entrance or exit ramps.

  • corridor_route character, the corridor route name. All roadway nodes with the same road and direction-of-travel are grouped into corridors.

  • corridor_dir character, the corridor route direction. One of "EB", "NB", "SB", or "WB"

  • datedate, the date the configuration was accessed

Details

Additional documentation on the IRIS system can be found on MNIT documentation page.

See also

Other loop sensor functions: pull_sensor(), pull_sensor_ids()

Examples

if (FALSE) {
config <- pull_configuration("in-memory") # Assign to an object
pull_configuration("within_dir") # No assignment necessary
}