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.

There are three Network Screening applications available for users to choose from: Segments, Sliding Window, and Intersections. Depending on the package your organization has purchased, you may not see all three available in your instance.

In Network Screening - Segments, all roadways are segmented, allowing users to compare smaller portions of a roadway with similar characteristics, rather than evaluating an entire route. In this application, intersection crashes are removed from the analysis.

How each agency’s roadways were segmented is documented in our Agency-Specific Library, available here.

In Network Screening - Sliding Window, users can compare roadways in their network within a window size of .1 to 10 miles. In this application, both roadway and intersection crashes are included in the analysis.

In Network Screening - Intersections, users can compare the performance of intersections in their network. In this application, only crashes occurring within the intersection boundary are included in the analysis.

How each agency defines intersections is documented in our Agency-Specific Library, available here.

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.

Note: The default sliding window size is organization-specific and may differ from the examples shown in this documentation. It can be adjusted to meet organizational needs.

(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 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. 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 in the bottom right corner of the screen.

(The 10,000-sites warning message in regular Network Screening)

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. Simply click the icon to view the message. The indicator disappears once the result set is reduced to fewer than 10,000 rows.

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

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

The map toolbar in Network Screening lets you customize the map, find locations, filter your screening by area, and export your results. It includes Map Settings, Layers, Map Search, Zoom Controls, the Polygon Tool, the Circle Tool, Filter to View, Zoom to Extents, and Download.

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 Alternative Design, Crash Query, Predictive Analysis, or Safety Analysis, 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 Network Screening flyout, with the available applications that the selected segment can be opened in.)

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

To save a screening, select the “Save” button in the top right corner of your screen.

Name your screening and indicate which category (or create a new one) to save it in. Saved screenings without assigned categories are saved to the "Uncategorized" category by default. New categories can be added from within the Save Network Screening pop-up menu.

(Pop-up menu to save a screening)

Once a screening has been saved, new menu options are available in the top-right corner of the screen within saved screenings.

The menu options from within a saved screening are:

To access your saved screenings, select the home button in the top-left corner of the Advanced Network Screening application.

(While in the Network Screening application, select the “Home” icon next to the applications menu)

This will take you to a page displaying the screenings you’ve saved and those shared with you.

(Saved screening page in Network Screening)

To share a screening, select the three dots next to a query from within the library. Select “Share,” then “Manage users,” and enter the email addresses of the users you’d like to share the query with in the pop-up box.

(Click the three dots next to a saved screening to share, edit the name/category, copy the screening to Advanced Network Screening, or delete it)

Indicate the level of access you want shared users to have to the screening: edit or view. Select "Done" when you’re finished. Sharing screenings can also be managed from within a saved screening using the “Share” icon in the top-right corner.

Screenings can only be shared with individuals who have access to that AASHTOWare Safety instance.

Note: If your organization doesn’t have Advanced Network Screening, the “copy to Advanced” option will not work.

Regular Network Screening supports the following download options: .png, .shp, .kmz, Report (.pdf), Worksheet (.xlsx). These download options are available under the Download icon in the top-right corner of the screen, or on the map download icon from the Map Toolbar.

(The Downloads dropdown in the top right corner of the screen, displaying the different download options.)

(The Downloads dropdown from the map download, displaying the 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.)

Download an image of the current Network Screening map as it appears on your screen.

A shapefile (.zip) of your Network Screening project. The .zip file includes .prj, .dbf, .shx, and .shp files.

A file containing the locations from your screening, including all segments that meet your filter criteria and all columns of data in your ranking table.