A desire line visualizes the values for relations between zones (From zone to To zone). The values displayed on the desire line may derive from different origins.
- From a demand matrix (for example to visualize the demand between zones)
- From a skim matrix (for example to visualize the journey time between zones)
- As a value from the network model itself (for example the direct distance between zones)
- From a zone attribute of the From zone or the To zone of the relation (for example to illustrate the From zone\origin traffic to other zones)
For each OD pair you can draw both a desire line link as well as one or more desire line bars for a proportional display of the values (User Manual: Displaying desire lines).
The display of desire lines is useful for illustrating demand matrices and indicator matrices in the network editor. This is how you can get an overview, which OD pairs (From zone to To zone) are especially in demand, for example. The example shown in Image 262 shows the travel demand between the zone Oppidum and all other zones. It is clear, that there is an especially high demand between the zones Oppidum and B town.
Image 262: Desire line with bars scaled at the demand between zones
The desire line is drawn on the linear distance between the zones. If you are interested in the exact course of the paths between origin and destination zones, use the Shortest Path Search (User Manual: Searching for and displaying shortest paths).
Combined with the OD pair filter (User Manual: Exception: Filter for OD pairs) the display of the desire lines on OD pairs, which correspond to the filter criteria, can be confined. As an alternative, the number of the OD pairs displayed can also be displayed via a classified display (User Manual: Specifying basic settings for the Network editor window).
Furthermore, the desire line can also be drawn classified. As shown in Image 263, you can highlight OD pairs with a high traffic demand with colors, for example.
Image 263: Desire line with bars classified according to the demand between zones
