To Check Sight Distance Using a Zone of Visual Influence

Use this command when you need to determine if a vertical object, such as traffic light or a tower, can be seen from within a certain radius.

You can also use this command to determine how far a driver can see from a stop line at an intersection.

To check the validity of the designed terrain, this check is typically performed against a finished ground surface, or a composite surface (a corridor surface pasted into an existing ground surface).

This command creates hatch patterns on the current drawing layer to indicate the different levels of visibility.

1. Set the drawing to the layer on which you want to create the hatch patterns.
2. Click Analyze tabDesign panelVisibility Check drop-downZone Of Visual Influence Find.
3. Select a surface, or press Enter and select a surface from the list.
4. At the command line you are prompted to specify the following:
   • location of the object
   • height of the object
   • radius of the vision extent

   After the command is completed, the colored areas (hatch patterns) on the surface within the specified radius indicate the following:

   Color	Visibility
   Green	the entire height of the object is visible
   Yellow	the object is partially visible
   Red	the object is not visible