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Simunto Via

Modal Split Analysis

Requirements: Network, Events, Optionally: Shapefile with zones. Aggregation plugin.

Data preparation

  1. Add the network file, events file, and if you have the zones shapefile, to Via.
  2. Create the following layers:
    • Network
    • Agents (from Events)
    • Vehicles (from Events) base visualization
  3. Create an OD Aggregation layer and open its settings dialog.
  4. If you added a Shapes file with zones, select it in the Aggregation Zones section. set shapes as aggregation zones
  5. Switch to the Attributes section and edit the default Counts attribute to use the Trips data source.
    Edit the Counts aggregation
  6. Create an additional aggregation attribute, name it carShare, use the Trips data source and set it to calculate the aggregation as Share, with Trip Mode containing car.
    Create car-share attribute
  7. Create an additional aggregation attribute, name it ptShare, use the Trips data source and set it to calculate the aggregation as Share, with Trip Mode containing pt.
    Create pt-share attribute
  8. Click on OK to calculate the attributes.

Visualization

  1. Open the settings dialog of the Aggregation Layer.
  2. Switch to the Zones section and set the color to use an attribute mapping on the attribute carShare (out) with a color ramp between 0.0 and 1.0.
    The carShare (out) describes the outgoing-value of the OD-aggregation for each zone. As we used Trips as data source, this describes the number of trips starting in each zone, as each trip is an OD relation between two zones. Set zones color
  3. Switch to the Labels section and enable the Show Labels option. Add two parts to the label text, showing the carShare (out) and ptShare (out) as attributes and add matching prefixes before them. Set zones labels
  4. Close the settings dialog by clicking on OK. This should result in a visualization similar to the one shown below, where the zones color represent the car-share, and a label showing the values of car- and pt-share.
    example visualization

Since Via 20.3, it’s also possible to visualize the shares as small charts within the zones, e.g. small pie charts.

Alternative Visualization

  1. Open the settings dialog of the Aggregation Layer.
  2. Disable the display of zones by unchecking the Show Zones checkbox in the Zones section.
  3. Switch to the Symbol section and check the Show Symbols checkbox.
  4. Set the color of the symbol to use an attribute mapping, choose the attribute ptShare (out) and set a color ramp between the values 0.0 and 1.0.
    set symbol color
  5. Set the size of the symbol to use an attribute mapping, choose the attribute Counts (out) and set sizes for 0.0 and some upper bound.
    set symbol size
  6. Set the label in the Labels section to show the value of ptShare (out) and chose the position Middle-Center.
  7. Close the settings dialog by clicking on OK. You should now have a visualization similar to the one below, where the color of the symbol reflects the modal share of pt, and the size of the symbol reflects to total number of trips starting in each zone. In addition, the pt-share will also be shown as label on top of the symbol.
    set symbol size