AADT

Data dictionary for the AADT module, covering response fields returned by the getModeledAADT API.

The table below lists all fields in the getModeledAADT API response. Each row in the response represents one road segment, one vehicle group, and one year.

Field

Description

Data type

Defined value set

AADTbyVehicleGroup

Array of objects representing the AADT of each vehicle group. Each object contains:

  • VehicleGroup (string): vehicle group name.

  • AADT (integer): estimated annual average daily traffic value.

  • PredictionIntervalLower (integer): lower bound of the relative prediction interval for the AADT value.

  • PredictionIntervalUpper (integer): upper bound of the relative prediction interval for the AADT value.

  • EstimateMethod (string): indicates whether the value is based on observed ground truth or projected ground truth.

ARRAY

VehicleGroup: "Universal", "Heavy", "Medium"

EstimateMethod: "observed", "projected"

CardinalDirection

The direction of the road segment.

STRING

"N", "NE", "E", "SE", "S", "SW", "W", "NW"

Direction

Direction of travel of the road segment. For non-directional analysis (isDirectional = false), returns 0.

INTEGER

1, -1, or 0

EstimateMethod

Indicates whether the AADT value is anchored to observed reference counts or produced via time series projection from observed years.

STRING

"observed", "projected"

ISO_3166_2

The ISO 3166-2 code of the zone.

STRING

—

PredictionIntervalLower

Lower bound of the 90% prediction interval, expressed as a relative percentage of the AADT value.

INTEGER

—

PredictionIntervalUpper

Upper bound of the 90% prediction interval, expressed as a relative percentage of the AADT value.

INTEGER

—

RoadType

The road type of the returned data as defined by OSM.

STRING

"motorway", "trunk", "primary", "secondary", "tertiary"

SegmentId

Unique identifier for the road segment (Geotab edge ID derived from OSM ways).

STRING

—

Year

The year of applicability for the AADT value.

INTEGER

—

ZoneDescription

Description of the zone when available, based on zone type (for example, state name, county name, city name).

STRING

—

ZoneId

The zone ID for which the data is returned.

STRING

—

ZoneType

The zone type for the returned segment.

STRING

"State", "County", "City", "CTR", "ZIP", "TAZ", "Custom"

AADT Value Rounding

Raw AADT model predictions carry uncertainty that varies by road type, location, and data availability. Presenting unrounded predictions to customers overstates the model's precision and exposes them directly to prediction noise.

Reported AADT values are rounded to a precision level derived from the width of the 90% prediction interval (PI). The approach follows standard scientific convention for reporting measurements under uncertainty: the reported value should be no more precise than the uncertainty itself warrants. Specifically, the rounding precision is set to the order of magnitude of the PI half-width, with one additional decimal place retained when the leading digit of the half-width is 1 (the two-significant-figure rule for uncertainty).

Previous
Next