You can define any number of visibility sightlines based upon pre-defined types. The sightlines may optionally use user-definable data tables or pre-defined equations, some of which have user-definable parameters. All active sightlines defined in the standard are created automatically when you place a roundabout. Thereafter they may be individually switched on or off to facilitate easy analysis.
Click Visibility Analysis in the left hand pane. The Visibility Analysis page is displayed.
There are a number of sightline types available, not all of which are appropriate to all national standards. They include the following:
- Approach Stopping Sight Distance
- Forward Circulatory Visibility on Approach
- Backward Circulatory Visibility on Approach
- Circulatory Visibility on Roundabout
- Next Exit Crossing Visibility on Approach
- Approach Crossing Visibility
- Backward Fastest Line Visibility
- Minimum Backward Fastest Line Visibility
- Previous Entry Visibility on Approach
- Previous Entry Line of Sight
We recommend that if the sightline changes or additions you wish to make require new tables or equations then these should be created first.
If you have some sightlines already defined then you may click the [+] next to Visibility Analysis in the left hand pane to expand the list.
Click New to create a new sightline.
Click Tables to create or edit a data table.
Click Equations to create or edit an equation.