Parameters of the line blocking procedure

In the drop-down list, you can select one of the line block versions of the network for line blocking calculation. The attributes Number and Code of the selected line block version are displayed (Attributes of line block versions).

The attribute Line blocking time period is displayed for the block version selected (Attributes of line block versions).

Note

If the line blocking time period differs from the analysis period, a warning will be displayed concerning potential subsequent PuT operational indicator calculations.

If this option has been selected, only active vehicle journey sections are considered for line blocking.

Note

Additionally, you can reduce the amount of considered vehicle journey sections to the unbound vehicle journey sections only.

If this option has been selected, only unbound vehicle journey sections are considered for line blocking.

Note

Additionally, you can reduce the amount of considered vehicle journey sections to the active vehicle journey sections only.

If this option has been, closed blocks are calculated (Fundamentals: Open and closed blocks).

Note

This option is only provided if no annual calendar has been selected.

If this option has been selected, blocks start at a depot and end at a depot. Start depot and end depot do not need to be identical.

Note

This option is only provided if the option Build closed blocks has not been selected.

If this option is selected, you can choose a user-defined block item type from the drop-down list (Creating a block item type). As the first block item, an item of the select type is added to each open PuT line block.

Note

The option is only provided if the Build closed blocks option has not been selected and if at least one user-defined block item type has been defined.

If this option is selected, you can choose a user-defined block item type from the drop-down list (Creating a block item type). As the last block item, an item of the select type is added to each open PuT line block.

Note

The option is only provided if the Build closed blocks option has not been selected and if at least one user-defined block item type has been defined.

If this option is selected, the orientation of the line blocks with the property Regard running direction will be checked at the end of the line blocking procedure:

• For closed line blocks, the check verifies whether the first vehicle journey block item always starts with the same orientation.
• For a line blocking time interval of more than one day the check additionally verifies whether the orientation is the same for each occurrence of the vehicle journey section.

If one of these criteria is not satisfied, the status direction fault will be assigned to the line block.

For line blocks generated by the line blocking procedure, the attribute Regard running direction is set = true.

Via the options, you can influence the structure of transfers between vehicle journey sections in the line block (Fundamentals: Decomposition of the flow into blocks).

Differentiated duration of layovers

The distribution of the layover times is as irregular as possible, in other words, there are more short and long layovers than average layover times. The aim of this is to obtain long layovers which can be used as maintenance time slots.

Even duration of layovers

The distribution of the layover times is as even as possible. Such blocks are exceptionally resistant to disturbances.

Line purity

It is attempted to only run vehicle journeys of the same line in a block or to at least avoid line changes within a block as often as possible.

No specific requirements

In this dimension, no requirements are set concerning the result.

Even line blocks

Select this option if you want Visum to calculate line blocks that are as similar as possible for each calendar day of the block time period. This makes it easier to perform line blocking in real operation. In addition, line block readability is improved.

Note

This option is only available if your line blocking time interval is longer than a day.

If closed blocks are generated, you can use the options to influence the duration of the blocks (Fundamentals: Decomposition of the flow into blocks).

Note

These options are not available if Even line blocks is selected in the Secondary chaining criterion section.

Preferably build long blocks

Blocks have as many block days as possible. This means that the single vehicles traverse multiple line paths. In the most extreme case, all vehicle journeys of a partition are covered by a single line block.

Preferably build short blocks

Line blocks have as few blocking days as possible.

No specific requirements

In this dimension, no requirements are set concerning the result.

If this option is selected, the layover time is used as specified for the block version (Attributes of line block versions).

Select this option to make settings for the interpretation of the layover time.

Note

This option is only available if you select Consider pre/post-preparation times on the Layover times tab (Attributes of line block versions).

Select this option to make settings for the interpretation of negative layover time.

Note

The entry of a negative layover time might lead to time faults during the block check (Fundamentals: Line block check). You can avoid this problem by adapting the timetable or creating additional vehicle combinations.

Only one of these options is available.

The fixed part of minimum the layover time in minutes that must not be fallen short of.

Note

This option is only available if, on the Layover times tab, under the attributes of the block version, the options Consider pre/post-preparation times (Attributes of line block versions) and Soft interpretation of pre/post-preparation time are selected.

The share of the negative layover time that leads to a timetable change is indicated in minutes. The value is automatically given a minus sign.

Value indicates the variable part of the minimum layover time, by which the layover time can be reduced if costs can be saved. Together, the fixed and variable parts form the minimum layover time.

If this option has been selected, the succeeding trip can only be a vehicle journey which is run by the same operator.

If this option has been selected, the succeeding trip can only be a vehicle journey using the same transport system.

If this option has been selected, the succeeding trip can only be a vehicle journey of the same line.

The list contains all vehicle combinations of all possible combinations of the items operator, transport system, and line, depending on the options selected above.

Empty trip-TSys

Use the drop-down list to select the empty trip transport system for the respective combination.

Note

In the section Transfer empty trip transport system of the marked row, you can transfer the setting of one row to other rows.

You can copy a transport system selected in the list to other vehicle combinations. Select the rows to which you want to transfer the empty trip transport system of the selected row:

• To all rows
• To all rows with the same vehicle combination
• To all rows with the same operator
• To all rows with the same transport system
• To all rows with the same line

In this list, you can enter the weight by cost component which shall be regarded during the cost calculation.

Weighting factor by cost component

List of line block attributes, whose attribute value is regarded if the coefficient for the attribute is greater than 0.

Attribute values; each of them is multiplied with the particular coefficient and the line block attribute value.

Line blocking terminates after the entered number of iterations.

As convergence criterion, enter the number of iterations, after which the solution must be improved to iterate further.

The higher the number of solutions which are determined per iteration, the higher the quality of the result to be expected.

Note

Both the time required for the calculation and the required memory capacity will increase in this case, however.

In the case of otherwise unchanged settings, you determine a different result with a new starting value. With the same starting value and unchanged settings you can reproduce an existing result.

If the option has not been selected, a reference solution is used for the line blocking.

If the option has been selected, you can select and use a block version of the network in the list as reference solution. The attributes Number and Code of the selected line block version are displayed (Attributes of line block versions).

Notes

• This option is available if you have selected Line blocking with vehicle interchange.
• A block check is run for the reference version. If it does not contain a complete coverage of valid blocks, a warning is displayed and the procedure is terminated (Fundamentals: Parameters and convergence).

In each row, this column contains a cost component of the objective function.

• Costs: Objective function of line blocking without vehicle interchange. This especially comprises the number of vehicles per vehicle combination as well as the service km and empty km and service times and empty times, as well as the layovers within and outside of a depot
• Number of vehicle units: Exceeding the predefined number of available vehicle units
• Consideration of volumes: Too low capacities (total or seats) regarding the OD demand
• Line purity, local definition: Number of transfers between the different lines
• Line purity, global definition: Number of different lines in a block
• Number of vehicle combinations per line: Number of different vehicle combinations used on the same line
• Regularity: Number of vehicle journey sections, who's vehicle journey section occurrence lies in at least two different blocks or blocking days
• Structural properties of line blocks: There are three evaluated structural properties:
• Number of block days (if the option Preferably build short blocks or Preferably long blocks is selected on the Properties of line blocks tab)
• Empty runs should be arranged as early as possible within a transition between vehicle journeys
• If mandatory user-defined activities are scheduled, they should be arranged to last less frequently and for longer periods of time rather than more frequently and for shorter periods of time.
• State of charge: It is evaluated how often, how strong and how long the state of charge becomes smaller than the required minimum state of charge. Negative values are weighted particularly strongly, because this would lead to blocks with limit faults in the end.

• Difference from reference solution (only when a reference solution has been specified): Difference to this reference solution in form of deviating transfers between vehicle journey sections.

In this column, you can enter a factor for each component after double-clicking the respective row. This way, you specify the weight with which the component enters the objective function.

Attribute for number of vehicle units

Use the button to select the vehicle units attribute which determines the number of vehicle units.

Minimum state of charge

In the input field, enter the value for the minimum state of charge that is used in the calculation of the objective function.

Attribute for volume

Use the button to select the vehicle journey items attribute which determines the volume.

For dimensioning of the vehicle combination use

Select the desired option in case the volume of a vehicle journey section is higher than the capacity of the scheduled vehicle. This option refers to the objective function component Consideration of volumes.

Average volume

If this option has been selected, the average capacity overload over all vehicle journey items of the section will be evaluated.

Peak volume

If this option has been selected, the peak capacity overload over all vehicle journey items of the section will be evaluated.

You specify how the vehicle capacity is included in the calculation. You can also specify not to account for the vol/cap ratio.

Use total capacity

Select this option for consistent use of the total capacity as capacity.

Use the seat capacity

Select this option for consistent use of the total seating capacity as capacity.

Capacity switchover due to the attribute value

Select this option to choose an attribute of vehicle journey items whose value indicates the criterion used to determine the capacity.

• For values greater than null, the total capacity is used.
• For values smaller than null, the seating capacity is used.
• With null, the capacity is not included.

Attribute for destination vol/cap ratio factor

Use the button to select the vehicle journeys attribute which determines the desired vol/cap ratio.