Own Expressions

You can create your own custom expression for routing. 

This is useful when not using Highways or Open Roads data (or you prefer not using the shortest distance).

Select Applications > Routing Tools > Settings > Own Expression.

To select the attribute on which to base your expression, first choose the 1. overlay and the relevant 2. schema column.

The Attribute can be interpreted in one of two ways: it either contains the actual speed to be used for routing or it contains a road class.

Specify the type in the correct field with its associated speed:

TIP: The Play icon is a Windows ‘DataGridView’ control; the arrow shows which line is being edited or will be deleted if you hit the Delete key.

 

If needed, change the speed units. Click Make Expression.

Routing Expression

The routing expression can be edited using the simple editor included with routing tools. Click “Show" to automatically load into the expression in the editor. 

To edit a saved configuration, select it from the drop-down box and make the necessary changes. Click Saveagain; the new changes will simply be overwritten on the old expression.

• To save a custom expression, assign a name to the expression and click Save.
  
• To load a saved expression, select it from the drop-down box and click Recall.
  

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