Note: This article outlines the functionality of regular “Network Screening” applications. To learn about Advanced Network Screening, see here.

The Network Screening applications are designed to help users rank and identify sites for further investigation and potential treatment across the entire roadway network, using an easy-to-use interface.

Network Screening - Segments, Intersections, and Sliding Windows use historical performance measures to analyze sites. Additionally, the Network Screening applications can analyze up to 10,000 sites at a time. Results in these applications are instant.

The Network Map displays the ranked segments/windows/intersections, color-coded according to standard deviation. Green represents the lowest value, yellow represents the mean (+1 standard deviation), and red represents the second standard deviation (Mean + 2 standard deviations).

(A screening generated with regular Network Screening - Segments, with the Network Map displaying the segments ranked by number of crashes in a specified county)

When conducting a Network Screening, it is easy to see the dates of historical crash data used to generate your screening results. By checking the Date Extents in the top-right corner of the screen, you can see the dates of the data included in your screening.

(The date extents for the data in Network Screening - Segments)

To modify the dates, click the Date Extents from the menu bar. Here, users can adjust the date range using one of the following options:

(Editing the "Other" date range option in regular Network Screening)

In Network Screening - Sliding Window, users can also adjust the window length by selecting the settings cog in the top right corner of the screen. The Network Screening - Sliding Window configuration setting allows users to control the number of sites to rank and adjust the window length size between .1 and 10 miles.

(Use the settings cog in Network Screening - Sliding Window to adjust the window size)

Rank your selected roadway by the following Performance Measures:

A comprehensive list of how each ranking criteria is calculated can be found in the Numetric Calculations Overview article. Columns that can be ranked are indicated by a down caret symbol (⌄) next to the column header. Columns without this caret are displayed for informational purposes only and cannot be used for ranking. Click on the column to rank the network by that performance measure.

Network Screening will load up to the limit set by your organization (maximum of 1,500 segments/windows/intersections) that meet your ranking and filter criteria. A more comprehensive list of all site rankings is available in the CSV download.

(A segment ranking window with the selected segments ranked by Crashes, with additional performance measures also displayed.)

Use the advanced filter bar to run custom roadway Network Screening requests. Search by recommended countermeasure, crash type, or any other crash or roadway attribute, and generate instant roadway rankings that tell you which roadways require your attention. When more than 5 filters are added, users can collapse them for a cleaner view.

(A Segment Screening for a given city, including only non-interstate crashes, ranked by Crash Rate - Yearly.)

In regular Network Screening applications, the search limit is 10,000 sites. This means the apps can analyze and rank up to 10,000 sites at a time. When a user’s search criteria returns more than 10,000 sites, the application cannot accurately evaluate the entire network.

When this occurs, an error message appears at the top of the screen near the filter bar. The message can be dismissed, but doing so does not resolve the issue. As long as the network includes more than 10,000 results, a small warning indicator remains visible in the bottom-right corner of the screen. This indicator disappears once the result set is reduced to fewer than 10,000 rows.

(The 10,000 sites warning at the top of regular Network Screening)

(The 10,000 sites warning indicator in the lower bottom right corner of regular Network Screening)

(This message in the bottom right corner of regular Network Screening will remain on the screen until the network is below the 10,000 result limit)

Crash-based filters remove only crashes from a site. They do not remove sites, so they do not affect the network size.

Segment/window/intersection and geographic filters remove roadways from the network and can trigger the 10,000-result limit, potentially resulting in incomplete rankings. To ensure accurate and complete rankings for larger networks, it is recommended to use Advanced Network Screening, which is designed to handle larger datasets and does not have a 10,000-result limitation

There are multiple options available in the map toolbar. Learn more about each one below.

Clicking the Map Settings icon (the gear icon at the top of the map toolbar) lets you customize your map settings. The Zoom Controls settings are set as your global default map settings across all applications.

(The Map Settings section of a Network Screening map)

Zoom Controls

Auto-zoom automatically zooms the map to the crash extents as filters are applied or removed. Toggle this feature off to prevent the map from auto-zooming.

When toggled on, “Switch to Satellite” automatically switches the map view to satellite when zoomed in a certain extent. Toggle this off to keep the map view consistent regardless of zoom view.

Polygon

Enabling the polygon setting “Show name” and “Show area (square miles)” displays the name and square mileage of any applied polygons in your screening.

To help select routes, users can use map features such as asset layers, which allow users to overlay various characteristics on the map.

(Asset layer displaying city boundaries on the map in Network Screening - Segments)

Use the map search to easily find locations on the map. Note: using the map search will not apply any filters to your screening.

Use the + and - zoom controls to easily zoom in and out of the map. Users can also use their mouse scroll to zoom in and out of the map.

Users can filter the map by drawing polygons to define geographic boundaries. To finish drawing a polygon, users must double-click the final point. Polygons can also be used to exclude the selected area from the screening. To exclude a polygon, select “inside” in the filter bar and change it to “outside.” Simply click a line of the polygon to adjust the shape.

Users can filter the map by applying circle filters to define geographic boundaries. Circles can also be used to exclude the selected area from the screening. To exclude a polygon, select “inside” in the filter bar and change it to “outside.” To adjust the radius of a circle filter, select the default “250 ft” in the filter bar and enter a new value for the radius.

When zoomed into a location on the map, users can use the Filter to View button to set a filter for the area currently displayed.

When zoomed in or out, users can use the Zoom to Extents button to return the map to display the current filter area (zooming in or out).

Download a .png file of the current map view in the screening, including any applied geo boundaries, circle/polygon filters, and displayed layers or assets.

Clicking on any site in your network displays the Location Flyout, which contains a summary of crash statistics, including the number of crashes, crash rate, crashes per year, eDPO, and location information.

(The Location Flyout in Network Screening - Segments)

Users can open a selected segment/window/intersection in either Safety Analysis or Crash Query, depending on the applications available to that user. To open a site in the selected application, click the Open In button in the location flyout and select the application from the list.

(The regular Network Screening flyout, with the available applications that the selected segment can be opened in.)

Regular Network Screening supports three download options: Report (.pdf), Worksheet (.xlsx), and Geometry zip (.kmz). All of these download options are available under the Download icon in the top-right corner of the screen.

(The Downloads dropdown, displaying the three different download options.)

Generate a downloadable Network Screening Report which contains the network ranking, and a breakdown of each segment/window/intersection, including the crash rate, crash ratio, crashes per mile, fatality rate, and serious rate, and distribution of crashes along the roadway grouped by severity, as well as a stacked bar chart indicating the mile point at which the crashes occurred.

(A sample Network Screening Segment Report.)

The Worksheet download allows you to download the entire ranking table of all sites that meet your screening criteria as an Excel spreadsheet file, including all the columns of data included in your ranking table. Within the application, the table will only display the top 100 sites; however, the downloaded Worksheet will include all sites that meet the filter criteria of your network screening.

(The worksheet download for a given screening, including the additional columns of AADT, BMP, EMP, Functional Classification, Number of Lanes, and Length.)

The Geometry Zip download allows you to download a .kmz file containing the locations from your screening. Like the Worksheet Download, the Geometry download includes all sites that meet your filter criteria, as well as all columns of data present in your ranking table. This .kmz file can then be loaded into any mapping application.