Connectors
Shortest path searches are conducted to determine the skims of paths between locations. The locations are implicitly connected to the network via the nearest active node. Therefore, only those nodes may be set active that enable a corresponding connector for all modes.
Public transport modes are connected via a PuT Walk transport system. Thus, for a stop area to be accessible, it must be connected to the appropriate transport system.
Skims
We recommend using static one-hourly assignments to determine the volumes of journey times per time interval. The modeling of motorized traffic in this case does not differ from that in aggregate models.
An alternative dynamic 24-hour assignment offers hardly any advantages in comparison, but is much more difficult to calibrate. A stable and robust assignment with a low gap (less than 10-3) is particularly important for calculating demand so that convergence can occur.
The determination of journey times in public transport is based on stop area matrices. The timetable can be timetable-base or headway-based for this purpose. The modeling of PuT connectors is not necessary. Based on the schedule skeleton, intertwined destination and mode choice is performed, the utilities of which are based on temporally differentiated shortest paths between locations.
Structural data
Structural data is modeled as activity locations, and their structural potentials are saved to the attraction potential attribute. Identifying activity locations is not always easy; it depends on data availability. Most often, existing aggregated data is disaggregated based on building layers, POIs, or the like. Once buildings are classified, activity-specific potentials can be estimated.
