The Over-representation Report compares the crashes in one area, such as a city, county, or district, with the larger areas it's in, such as the county, district, and state. It highlights the crash types and characteristics that make up a larger share of crashes in your area, so you can quickly see what stands out. This article explains how the report works and how to create one.
ℹ️ Note: The report needs one geo filter with one value, such as a City (Geo) filter set to a single city. Drawn polygons don't count. If the query has no geo filter, or the geo filter has more than one value, the Over-representation option is grayed out. Learn more in Location Filters - Geo vs. Non-Geo Filters.
How the Report Works
The report shows every metric in your Metrics tab, with these columns:
Filtered: Your area, from the geo filter, with the crash count and the percent of total crashes.
Larger areas: The same metric for the larger areas your area is in, such as the county, district or region, and state. Which areas appear depends on your organization's configuration.
The metrics are shown as a percent of total crashes, so you can compare areas of different sizes.
A value is highlighted when it's at least 5 percentage points higher than, or at least twice, the same value in the next larger area.
For example, Local roads make up 58.27% of the crashes in Madison and 50.21% in the county, so Madison's value is highlighted. The county's value is also more than 5 points higher than the region's 43.93%, so it's highlighted too. Values lower than the next larger area aren't highlighted.
(The Highway Type (On) metric, with the Filtered, County, Region, and State columns and the highlighted values)
The report uses each crash's geopoint. If a crash's reported location is inside the area but its geopoint is outside it, the crash isn't included, so counts can differ from a non-geo location filter for the same place.
Create an Over-representation Report
Set up your query with one geo filter value, and select the metrics you want in the Metrics tab.
Click the Download icon (down arrow) in the top-right corner, to the left of Save.
Click Over-representation.
(The Over-representation option, grayed out because the geo filter has two values)
4. In Report Options, enter a Report Title (it starts as your query name) and, optionally, Requested By. If your query has charts, you can select Include Charts Below Metrics.
5. Click Create Report. A preview of the report opens.
6. Review the report. To save it, click Save & Download in the top-right corner. To go back to Crash Query and change your query, click Back in the top-left corner.
The PDF downloads to your computer, and the report is saved in Reports under Reports > Archives, where you can download it again.