Assign Network Setup

4.2 Assign Network Setup

The steps to prepare an Assign Network are described in this section. To create a new Assign Network, a Network and an Assign Volume Bin are needed. The Network is also referred to as the Basic Network. Network Routes can be used as Fixed Routes. If the Assign Volume Bin has not yet been prepared, one can be created as part of the Assign Network Setup.

There are two general cases: Case 1: Create Assign Network Bin First and Case 2: Create Assign Volume Bin First. Both cases are covered in the steps described in this section.

Step A: Prepare Basic Network

Prepare a Basic Network (or Network) in the Network Setup Tab. Refer to the SIDRA INTERSECTION User Guide for preparing a Network. Create Routes for Fixed Routes in the Route Setup Tab, if required.

Ensure that there is at least one feasible route between O-D Pairs for MCs with O-D Volumes. A feasible route for an MC is formed when the MC's movement is enabled for all movements defining the route between the O-D Pair.

Step B: Prepare Assign Volume Bin

The steps to prepare an Assign Volume Bin are described in this section. An alternative order of steps is to skip this Step and proceed directly to Step C Prepare Assign Network and return to this Step at some other time to complete the setup of the Assign Volume Bin.

Step B-1: Add Assign Volume Bin

In the Volume Store-Assign Volume Bin Tab, click Add Bin to create a new Bin. Specify the number of Zones when asked by a dialog. A new Bin will be created in the Project Pane.

Step B-2: Assign Bin Setup

Click on the Assign Bin Setup in the Project Pane to open the Assign Bin Setup dialog.

• Bin Data Tab: Enter the Assign Volume Bin Data. Note that Bin IDs must be unique.

• Movement Classes Tab: Set the Movement Classes of the Bin.

• Zone Data Editor Tab: Set the Zone IDs, Names and Titles. The Zone IDs must be unique. Add or Delete Zones if needed.

• Properties Tab: Use the Bin Information field for documenting notes regarding the Bin.

Step B-3: O-D Volumes

Click on the O-D Volumes in the Project Pane to open the O-D Volumes dialog.

An Assign Volume Bin can contain multiple O-D Volumes. A default O-D Volume will be created for a newly created Assign Volume Bin which can be modified or deleted, if desired.

Setup the O-D Volumes in the Bin.

• O-D Volumes in Bin:

  • Click the "plus" button to create a new O-D Volume

  • Alternatively, click the "calculator" button to create a new O-D Volume using the Assign Volume Bin Calculator (existing O-D Volumes will be needed for the Calculator)

  • Existing the O-D Volumes in the Bin can also be cloned and deleted.

• Movement Class: Movement Classes enabled for the Bin will be available for selection. Select a Movement Class for data entry.

• Enter the O-D Volumes Data for the Movement Class.

  • Assign O-D Volumes Tab: Choose the preferred Matrix Type. Enter the Assign O-D Volumes.

  • Assign O-D Growth Rates: Enter the Assign O-D Growth Rates. The growth rates can be specified for Generation, Attraction or both i.e. Furness Method. If the Furness Method is selected, specify the Furness Settings, Percentage Stopping Condition and Maximum Number of Iterations.

  • Fixed O-D Volumes Tab: Choose the preferred Matrix Type. Enter the Fixed O-D Volumes.

  • Fixed O-D Growth Rates Tab: Enter the Fixed O-D Volumes.

For Assign O-D Volumes, Fixed O-D Volumes and Fixed O-D Growth Rates: Values from an MS Excel spreadsheet can be copy-pasted into the table.

• Click on 'Copy O-D Volumes to Clipboard' to copy the full table and paste (Ctrl-V) the values to an MS Excel spreadsheet or to another O-D Volume table.

• Hold Shift or Ctrl and click on cells on the table to select cells of the table. Ctrl-C to copy the selected cell's values to clipboard.

• To paste a table or parts of a table into the O-D Volumes dialog or to an MS Excel spreadsheet, select the top-rightmost cell and Ctrl-V.

Step C: Prepare Assign Network

In the Assign-Assign Setup Tab, click Add Assign to create a new Assign Network. The Add Assign Network Configuration Wizard will open.

• Select Network: Select a Basic Network to be converted to an Assign Network. Double click the Network; or select and click Next.

• Setup Assign Volume Bin: Select the Assign Volume Bin created in Step B. To select the Assign Volume Bin, double click the Bin; or select and click Next.

There is an option to Create a New Bin during this stage of the dialog, rather than using the Bin created in Step B. Use this option to create a new Bin, set the Bin Name, number of Zones and Bin Folder; and, click Next. When the Assign Network is completed, edit the newly created Bin in the Assign Volume Bin Tab as described in Step B.

• Connect Zones: Select and drag Zones from list into the Configuration Pane. Click [x] next to the Zone in the list to remove the Zone from the Configuration Pane. Connect Zones to an External Leg of the Network. Click-hold on the edge of the Zone, move the mouse pointer to the edge of an External Leg and release to establish a Zone Connector. Click [x] on the External Leg to remove the Zone Connector. Click Next to proceed. The action to Connect Zones is the same as connecting Sites when creating a Basic Network.

• Finalise the Network: Enter the Name and ID of the Assign Network. Click Finish to create the Assign Network. The newly created Assign Network will appear in the Project Pane.

Step D: Configure the Assign Data and Assign Scenarios

In the Assign-Assign Setup Tab, select the Assign Network and click on Assign Data in the Network Input Section to open the Assign Data dialog. Set the following:

• Assignment Parameters Tab: Choose the Assignment Method and set the Assignment Parameters.

• Fixed Trip Proportions Tab: All Network Routes that can be used as Fixed Routes will be in the list. A Network Route must connect an Origin Zone to a Destination Zone for a Movement Class. Check Routes that will be used as Fixed Routes. Set the Fixed Trip Proportions for each Fixed Route. Fix Trip Proportions for an MC for an O-D Pair must add up to 100%.

With Assign Network selected, click on Assign Scenarios in the Network Input Section to open the Assign Scenarios dialog.

• Add an Assign Scenario.

• Click on the ID and Name cell of the Assign Scenario to modify them. IDs of Scenarios must be unique for the Assign Network.

• Set the Initial Volumes using the dropdown menu.

• Set the O-D Volumes for the Assign Scenario using the dropdown menu

• Select the Assign Scenario that will be used to process the Assign Network by using the radio button.

Step E: Process the Assign Network

Select the Assign Network and click on the Process button. Processing of an Assign Network takes time because it needs to process the Network several times to find the traffic assignment solution. Once processing is completed, the Assign Network outputs will be available. Review the Diagnostics Report to check if the Assign Network converged well.

Step F: Create the Assign Network Outputs

All Basic Network Outputs are available for an Assign Network. Access these Outputs from the Network Output, Network Site Reports, Network Site Display and Route Output Tabs. Refer to the SIDRA INTERSECTION User Guide for these Outputs.

Special outputs for an Assign Network can be accessed from the Assign-Assign Output Tab. Assign Outputs are available for All O-D Pairs, which includes Trip Performance, Trip Route Displays and Movement Displays. Use O-D Presets to create reports for specific O-D Pairs.

Creating Assign Reports and Displays

In the Assign Output Tab, click on the command buttons in the Assign Output Command Group to create Assign Output Reports and Displays, which include:

• Diagnostics Report

• Trip Performance Report

• Trip Route Displays

• Fixed Route Displays

• Movement Displays.

Click on the dropdown menu for each Command Button to access setting options for each Report/Display. Right-click on the header of the Trip Performance Report to manage the visible metrics in the Trip Performance Report.

In Trip Route Displays, right click on an Assign Route that was programmatically identified (i.e. not defined by a Network Route) to open a shortcut to 'Create a Network Route from Assign Route'. Use this command to create a Network Route, which can then be used to access various Route Performance Reports/Displays. Right-clicking on an open pop-up in the Trip Route Displays also accesses the 'Create a Network Route from Assign Route' command shortcut.

Defining O-D Presets

In the Assign Output Tab, click the O-D Presets command button to open the O-D Presets dialog. By default, an All O-Ds Preset is created the first time the dialog is opened.

• Click the "plus" button to create a new O-D Preset. A new O-D Preset will be created in the O-D Presets Section of the dialog. Double Click the O-D Preset to edit the name of the O-D Preset.

• There are three View available: Layout View, Matrix View and Column View. Select the preferred mode. Check or uncheck the Zero Volumes to filter O-D Pairs with zero O-D Volumes.

• In Layout View:

  • Hover the mouse pointer over a Zone to show its Generated Trips and they are depicted by orange lines (arrows point to the Destination).

  • Click on any orange line to define an O-D Pair to be included in the O-D Preset. The orange line will turn to a blue line to confirm the selection.

  • To remove a selected O-D Pair from the O-D Preset, click on the blue line connecting the O-D Pair. The blue line will turn to an orange line to confirm that the O-D Pair has been removed from the O-D Preset.

  • Right-click on a Zone to access shortcuts:

    • Show Attracted Trips for this Zone

    • Show Generated Trips for this Zone

    • Show All Trips for this Zone (i.e. Generated and Attracted)

    • Select All Visible Trips for this Zone (i.e. select all visible orange lines)

    • Deselect All Selected Trips for this Zone (i.e. deselect all blue lines)

• In Matrix and Column View:

  • Use the Origin and Destination Zone Filter to manage the visible Zones.

  • Check or uncheck cells to include or exclude O-D Pairs.

    • In Matrix View: Double Click on Matrix Row and Column Headers to check/uncheck their associated O-D Pairs.

    • In Column View: Click on Column Headers to arrange Column Entries alphabetically (Click Header to toggle arrangement order).

• Click OK or Apply to save the O-D Preset. The O-D Preset is saved as an attribute of the Assign Volume Bin. The O-D Preset will be available for any Assign Network that is linked with the Assign Volume Bin.

• Optionally, Assign Output Reports and Displays can be created for the selected O-D Preset while in the O-D Presets dialog. Click on the "Create Reports" button in the O-D Presets dialog to open a "Create Selected Reports" dialog. Use the sliders to select or deselect Report/Display types. Click on the "plus" icon under each Report/Display type to select the desired performance metrics. Click "Create Selected Reports" to close the O-D Presets dialog and open the selected Reports/Displays. All Fixed Routes for the O-D Preset will be included in the Fixed Trip Displays.