Screening is the process of identifying and ranking crash locations from a highway network. Sites identified as experiencing higher than expected frequency or rates of crashes are the locations most likely to benefit from the implementation of countermeasures. After creating the safety profile and defining the hotspot rule, next step is to perform the Network Screening.
The screening window consists of two tabs:

• Manage Scenarios: the screening scenario is created and necessary settings are made in this data window.
• Results:
  • Scenario Profile tab: consists of two data windows. The upper lists the 'Main Location-Results' while the lower lists the 'Secondary Location-Results'.
  • Hot Spots tab: As a results of a Network Screening, hotspots are identified and shown in this data window.

In order to perform Screening, follow these steps:

1. Right Click and select Insert to add a new screening scenario.
2. Enter a meaningful Scenario Name.

NOTE: The scenario name will be used  in the following steps of the analysis (i.e. Diagnostics).

1. Select a Safety Profile from the dropdown. The Safety Profiles listed in the dropdown are those that have been defined in the Setup> Screening> Profile Management window. Based upon the Safety Profile selected, the Screening Method field will automatically populate and cannot be modified in this window. Instructions for creating a Safety Profile are discussed in the Safety Analyst Setup chapter.
2. The Threshold Handle Rule and Hot Spot Rule fields are also set to default values; however, the different rules can be defined for these fields in this window.

NOTE: How to setup these columns are also described in the Safety Analyst Setup.

       3. Enter a value for % Above PM  (the percentage above the performance measures) field above which the locations will be identified as hotspots under this Scenario.

NOTE: For example if the user enters 5 in the '% Above PM' field, the top 5% hotspots will be identified.

       4. Right click and select Edit Scope and select the network scope for the screening.

 NOTE: The network scope to be selected in 'Edit Scope' popup window must be configured in Screening columns (Safety Analyst > Setup > Screening > Screening Columns) window.

       5. Click Save

       6. Right click and select Edit Crash Threshold.

       7. Enter the threshold values based on the functional class.

     8. Click  on upper left corner of the data window to calculate the results.

     9. To view the identified hotspot locations, switch to Results tab. Note that, Results tab, has also two tabs: Scenario Profile and Results. 

   10. Scenario Profile has two data windows. While upper window shows the main hotspot locations. The bottom window shows the secondary locations for the selected main location from the Main Location Results window

11. To visually observe the hotspot locations, click Hotspots tab. 

To display a hotspot location on the map, click a hotspot location in the Hotspots table on the left of the window.