Timetable-based assignment: Basis page

Element	Description
Calculate assignment	If this option has been checked, the assignment is performed. If this option has not been checked, the assignment is not performed. Note You may, for example, calculate only skim matrices or perform connection export.
Calculate skim matrices	Select this option to calculate the skim matrices selected on the Skim matrices page (Timetable-based assignment: Skim matrices page).
Analyze risk of delay	If the option is selected, the risk of delay is analyzed after assignment. You can make further settings on the Risk of delay page (Timetable-based assignment: Risk of delay page).
Calculate service frequency	If this option has been selected, the service frequency is calculated for each OD pair. The frequency of service indicates how often a supply operates on a relation (Fundamentals: Skims of frequency). The service frequency by OD pair can be displayed in the Service frequency column of the Paths > PuT OD pairs list.
Use connector shares	If this option is selected, the assignment is calculated with a proportional distribution of the transport demand across the connectors (Fundamentals: Distribution of the travel demand to PuT connectors). Notes If you want zones to be accounted for with proportional distribution during the assignment, set the Share PuT attribute to 1 (yes). The shares of the connectors of these zones must be specified (Connectors: Basis tab). If this option has been checked, certain path attributes in lists are no longer defined clearly, e.g. access time.
Save detailed log files	If this option is checked, the assignment results will be saved to log files on the connection level.
Restrict demand data section	OD pairs considered for assignment Use the drop-down list to determine which OD pairs enter the assignment. All Only active OD pairs Only active origin zones Only pairs of active zones Note The setting specified for the OD pairs analyzed might differ from the setting for skim matrix calculation. If a restricting zone interval has been set for assignment, this will reduce the number of analyzed OD pairs even more. Restrict origin zones Here you can restrict the calculation to the demand of the selected origin zones. Thus only the selected rows of the demand matrix will be assigned. Notes If both entry fields are empty, Visum will assign the entire demand matrix. If only a single zone number is entered, Visum will use this value as the upper or lower limit respectively (half-open interval). The restriction applies to all iteration steps of the procedure: assignment, skim matrix calculation, and connection export, where applicable. In addition, the restrictions of the drop-down list OD pairs considered for assignment apply.
Assignment time period section	From – To Only that part of the timetable and travel demand are considered for assignment that lies within the specified time period. Note If a calendar is used, you need to select a weekday or a date (Selecting a calendar ). Pre-assignment period Time before the assignment time period within which the connections must start. Post-assignment period Period after the assignment time period within which connections must reach its destination.
Calculate paths from section	Connection search If this option has been checked, Visum determines the connections. Stored connections for DSeg If this option has been checked, Visum does not perform connection search, but will use connections precalculated in a previous assignment instead. In the list, click the demand segments with the connections you want to read in (Fundamentals: Opening of the timetable-based assignment: Export/Import of connections). Notes All imported connections are taken into account during assignment, regardless of the defined assignment time period. When calculating a skim matrix, no skim values are calculated for OD pairs with no demand, i.e. with no paths. File If this option is selected, connections are read in from a file (Fundamentals: Opening of the timetable-based assignment: Export/Import of connections). Via the button, select the desired file in *.con format. Notes Irrespectively of the specified assignment time period, the assignment will regard all connections read from file. You can also save connections to several files (Timetable-based assignment: Connection export page). Import fares If this option has been selected, fares stored by path or path leg are read from the file specified for File, if available. Visum calculates the impedances, skim values and choice on the basis of the fares read from the connection file. If this option has not been checked, Visum reads only the connections from the specified file. Impedance, skim values, and choice are calculated based on the fare model (Revenue calculation using the fare model). Notes This option is only provided if option File has been checked. In the connection file, fares are not stored per demand segment, i.e. for all demand segments the same fare per connection is read in from the file. If the connection file stores the fares on path leg level, the fare of the connection results from the total of the fares of the path legs. If the connection file stores the fares on path level, the fare of the connection is used without changes. Tip Fares are saved on path leg level or separately per path leg if, under Calculate > General procedure settings > PuT settings > Assignment in the Save imported fare data list, you click On path leg level (Settings for saving PuT assignment results).