Find the distance between all sensors based on corridor and direction. Essential for estimating travel time.

add_distance(config, interpolate_missing = TRUE)

Arguments

config: data.table, sensor configuration for multiple sensors
interpolate_missing: logical, default is TRUE. Whether to interpolate missing distance values.

Value

The original data.table with additional columns

distance the distance between the given sensor and the nearest upstream sensor in miles. Valid for Station node types only; all others will appear as NA.

Details

It is best to call this function on the entire sensor configuration data table; you can access the table with pull_configuration(). Non-station node types will be

Interpolation

Where upstream detector does not exist, or where distance is
beyond 3 miles, interpolate so as not to assume large VMT
merely because vehicles crossed an isolated detector.

If there is no upstream detector, or distance attributed is greater
than 1.5 miles, interpolate with the corridor median.

If, after interpolating with corridor median, distance is still
missing (i.e. NA for entire corridor), or distance attributed is
 greater than 3 miles (want a conservative assumption for how
 many miles of travel volume at a particular sensor depicts),
 interpolate with metro-wide network median.

Examples

if (FALSE) {

library(tc.sensors)

config <- pull_configuration()

add_distance(config, interpolate_missing = TRUE)
}