Overview
Percentile operators are available in Advanced Network Screening - Segments, Intersections, and Sliding Window. These operators identify locations that rank in the highest or lowest percentage range for a selected metric. Rather than filtering by a fixed value (for example, Crash Rate > 5), percentile operators rank locations relative to each other and return results that fall within the selected percentile.
This functionality allows users to answer questions like:
Which roadways are in the top 10% for crash rate statewide?
Which intersections rank in the highest 5% for fatal crashes within this county?
How Percentile Operators Work
Percentile operators require four inputs:
Filter
A filter derived from any of the following data types: Integer, Decimal, Currency (e.g., # of lanes, crash rate, ePDO, etc.)
Percentile Operator
The percentile operator (e.g., greater than or equal to, less than, between, etc.)
Percent
The percentile threshold or range.
Note: If multiple locations share the same value at the percentile cutoff, all tied locations are included in the results.
Comparison Area
The geographic area used to calculate the percentile ranking (e.g., state, county, city, other geo filters available). The comparison area determines what the selected locations are being compared against, not necessarily which locations are displayed in the results.
For example, if state is selected as the comparison area, every qualifying site in the state is used to determine the percentile threshold. Any applied Geo filters still control which locations appear in the results.
How to Use Percentile Operators
1. To use percentile operators, first choose your filter.
Any filters from the following data types will have the percentile operator option:
Integer
Decimal
Currency
2. Once you’ve selected the desired filter, click the operator to toggle on the “Percentile Operators” and select the desired operator.
3. Input the desired percentile value, select the comparison area, and apply the filter.
4. To add a comparison row, click the “Hide/Show Comparison Row” at the bottom of the Network Screening.
(Hide/Show Comparison Row)
5. Input the comparison area and value.
(The Comparison Rows pop-up)
(The comparison row displayed at the top of the network screening rows)
Example Percentile Screening Result
Application: Advanced Network Screening - Intersections
Filters added:
Crash Rate (percentile operator toggled on) ≥ 85% of State
AADT ≥ 100
County (Geo) = Specified County
Result:
Returns intersections with at least 100 AADT in the specified county with crash rates at or above the 85th percentile of crash rates statewide.
(Example percentile screening result in Advanced Network Screening - Intersections)