Crash Query - Over-representation Report

An overview of the Over-representation Report within Crash Query.

Greg Olsen avatar
Written by Greg Olsen
Updated over a week ago

Over-representation Report Overview

Over-representation reports allow users to compare a geographic region (city, county, or district) to the larger geographic region (county, district, state) in which it resides.

Over-representation reports highlight key differences in metrics between geographic regions, allowing users the ability to quickly identify potential crash types or crash characteristics that may be over-represented in the selected geographic region.

The over-representation report displays all of the metrics contained within the Query, broken into a number of columns. The first column, labeled Filtered displays the geographic region that was identified through the Geo Filter in the Query (either a city, county, or district/region - if configured for your organization). The next column(s) will represent the same metrics for the county, district and/or state in which the filtered geographic region resides.

In the example below, a city has been selected using the City (Geo) filter. The Filtered column contains the metrics for the filtered city. The next two columns, County and State represent the county of the selected city, and the statewide totals for each metric. The metrics are depicted as a percentage of total crashes, allowing for a meaningful comparison across different sized regions.

In the example below, the selected city has 3,224 Intersection Related crashes - which accounts for 44.45% of all crashes for the city. For the county and the state, Intersection Related crashes account for 43.43% and 39.28% of total crashes, respectively.

Over-representation reports highlight key differences in metrics between geographic regions. Any change of +/- 5% or 2x a given metric between geographic regions will be highlighted by the over-representation report. In the example below, Straight Horizontal Alignment crashes account for 68.47% of total crashes, compared to the county, which only experiences 42.64% of the same crash type. Because the number of Straight crashes is greater than 5% larger than the next lowest value, it has been highlighted. Additionally, the county has a significantly larger percentage of Unknown Horizontal Alignment crashes than the selected city, and the state - so it has been highlighted as well.

How to Generate an Over-representation Report

To generate an Over-representation report, follow the steps outlined below:

  1. Create the desired query, including customizing the Metrics sidebar to display the key crash metrics you would like to include in your report. Verify that you have a City, County, or District Geo filter on your desired query.

  2. Click the Download icon, located in the top right corner of your query.

  3. From the Report popup, select Over-representation (Note: if you are not able to select Over-representation report, it is most likely because you do not have a valid Geo filter applied to your query).

  4. Fill out the title and requestor field, and click Create Report

  5. The report preview will be displayed. Review the report, and make any changes in the initial query, if needed. To download the report, click the Save & Download button in the top right corner of the report.

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