3.6 Updating Input Data

Most input data in NERPM-AB is stored within the Visum version file. The MAZs in NERPM-AB are represented as the Point of Interest (POI) layer. TAZs are represented as Zones. The MAZ and TAZ level data is stored as the POI and Zone database (referred to as ‘list’ in Visum). The link and node level data are stored in the link and node lists. The lists can be viewed from the ‘Lists’ menu item as shown below in Figure 3-2.

FIGURE 3-2 PTV Visum List Menu

The data specific to tools are stored in their respective directories. For example, the seed sample and marginal control distribution data for PopulationSim are stored in the appropriate folder within the Population Synthesis directory (\tools\Population_Synthesis). The all-streets network data required for DaySim data tools are stored in the appropriate DaySim data tools directories (\tools\DaySim_Data_Tools).

The input data processing in NERPM-AB is streamlined using the Visum procedure sequence (Synthetic Population/DaySim Data Tools group). Visum interfaces with various tools via Python scripts. The tools need to be run in a specific sequence as outputs from one tool become input to the next tool. The exchange of data between various tools is fully automated. All tools need to be run only once for each model run. For subsequent runs, these tools need to be run only when specific inputs are changed. The flowchart below shows the input data workflow between various tools.

FIGURE 3-3 NERPM-AB V2.2 DATA PROCESSING WORKFLOW

Below are instructions on making a few example input data changes.

Adding 100 households to a MAZ

Assuming the tools in the Synthetic Population/DaySim Data Tools group have been run at least once, follow these steps to add 100 households to a MAZ:

• Open network editor