On this page and its subpages, you define settings for determining public transport connections.
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Element |
Description |
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Consider only active vehicle journey sections |
If this option has been checked, only active vehicle journey sections are considered for path search. Note This option affects the distribution of volumes. If there are simultaneous vehicle journeys on a time profile, the vehicle journey that has active vehicle journey sections is loaded when the vehicle journey is selected. If none of the simultaneous vehicle journeys on each loaded vehicle journey item has an active journey section, the vehicle journey is selected arbitrarily. |
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Maximum number of transfers |
Maximum permitted number of transfers for a connection from origin zone to destination zone. |
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Section Search procedure |
Use the drop-down list do specify the kind of search. Branch & bound search If this option is selected, all suitable connections in the entire analysis time interval are determined, even multiple connections with different impedances starting at the same time (Timetable-based assignment: Branch and Bound page). Notes Branch & bound search is suitable for the analysis of a time period. Use this search if you want to calculate an assignment with headway-based share (Timetable-based assignment: Headway-based supply page). Shortest path search If this option is selected, one connection per departure time is determined (Timetable-based assignment: Shortest path search page). Note Shortest path search is suitable for the analysis of a particular moment in time. |
Timetable-based assignment: Branch and Bound page
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Element |
Description |
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Search impedance |
For the Branch & bound search an impedance is used, which is calculated from a formula consisting of the following components:
The following might also be added:
Note The attribute is only provided if you have defined the Sharing transport system as station-bound (Roundtrip system) (Properties and options of transport systems).
Note If you have selected the option Use capacity restriction for vehicle journeys on the Extended consideration transport supply page, a Vol/cap ratio-dependent impedance will also be added to the SearchImp. You may enter a weighting factor for each of the addends. Via the Parameters button in the row of the transport system impedance, you can specify how the transport system-specific supplements will be calculated (Specifying TSys-specific impedances). Via the Parameters button in the row of the vehicle journey impedance, you can specify how the vehicle journey-specific supplements will be calculated (Specifying vehicle journey-specific impedances). This vehicle journey impedance is determined for each PuT path leg and added to the search impedance. The vehicle journey impedance can take a negative value which may not be higher than the sum of the values of journey time, number of transfers, and transport system supplement. Use the button next to the Sharing travel time entry to select an attribute of the allocated transport system which contains the travel time of the Sharing transport mode. Use the button next to the Sharing time at zone entry to select an attribute of the transport system which contains the average dwell time at a zone. In the Coefficient column, you should specify a value <1. Note The search impedance defined here differs from the impedance used in the connection choice procedure. |
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Transfer coefficients to PJT definition on the 'Impedance' page |
Use this link to transfer the factors of the individual search components in the Coefficient column to the PJT definition of the Impedance page for all demand segments and the parameter set which comprises all demand segments. The Transport system impedance and the Vehicle journey impedance are excluded from the transfer. Also transferred are:
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Time buffer for DRT path legs before public transport line path legs |
You can define the time buffer for DRT path legs that are covered before public transport line path legs. Enter a factor by which DRT ride time is multiplied and add a summand in minutes that is added to the product. |
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Section Cut off rules |
A connection is deleted if one of the following conditions is met: You may adjust the conditions with the help of factors and addends. Search impedance > factor • minimum search impedance + addend Connections are deleted if their search impedance is very high compared to the minimum search impedance of the OD pair. Journey time > factor • minimum journey time + addend Connections are deleted if their journey time is very high compared to the minimum journey time of the OD pair. Number of transfers > minimum number of transfers + addend Connections are deleted if their number of transfers is very high compared to the minimum number of transfers of the OD pair. |
Timetable-based assignment: Dominance page
These are the required conditions for the dominance of a connection when two connections are compared. In this case, the dominated connection is deleted.
Using the entry boxes, you may adjust the formula for comparison of search impedances.
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Element |
Description |
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Allow dominance between equivalent connections |
If this option is selected, equivalent connections that are dominated are not deleted if the connections only differ regarding their transfer stops. We recommend using this option with caution and together with the Use independence option on the Choice page (Fundamentals: Equivalent connections). |
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Priority of stop areas for transfers |
If this option is selected, the values of the input attribute Priority for transfers are considered for the dominance of connections. The smaller the attribute value is, the more important the stop area is for a transfer. For the first transfer at different stop areas, for two equivalent connections, the sum of priorities of the two stop areas involved in the transfer is calculated. The connection with the larger sum is deleted. If the sums are equal, the connection with the later transfer is deleted. |
| Priority of planned connecting journeys for transfers |
If the option is selected, the values of a selected (user-defined) attribute of the network object Planned connecting journeys are taken into account for the dominance of connections. The smaller the attribute value, the more important the planned connecting journey for a transfer. You can also specify whether the earlier or later transfer is selected if the values are equal. |
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Do not dominate direct connections |
If the option is selected, direct connections are not deleted. |
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Add wait time until arrival of c in search impedance of c' (recommended) |
Example: A passenger travels to town X by express train and has to wait there for a connection. A (partial) connection, for example with the regional train, is dominant, even if in town X the passenger changes to the same train as the passenger who arrived before with the express train. This option means that the wait time must be added for the (faster) partial connection - in this case with the express train. Here, the regional train is not dominated and not removed from the number of (partial) connections, as it is a viable alternative. |
Timetable-based assignment: Shortest path search page
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Element |
Description |
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Find connection with minimum search impedance |
If this option has been checked, the connection with the minimum impedance according to the current formula settings is determined for each start time. You may adjust the weighting factors for journey time and number of transfers in the formula. |
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Bi-criterion method |
If this option has been selected, the connection with the minimum journey time is calculated for each start time and any permitted number of transfers (all integers ≥ 0 and ≤ Maximum number of transfers). If the calculation returns identical journey times for different numbers of transfers, the program only stores the connection with the lowest number of transfers (dominance). |
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Times of departure for search |
For a zone, the connections are determined by a best path search performed for various start times. The start times result from the departures (max. 1/min, thus max. 1440/day) of the PuT lines from the connected stops. Use all existing If this option has been selected, a best path search is run for each departure time. Limit number to If this option has been selected, you can set the maximum number of departure times. If there are more departure times than defined as upper limit, the specified number of departure times is chosen randomly from all available departure times. Notes In case of a 24 hour assignment time period, the maximum number is 1440 = 60 minutes x 24 hours. Limiting the number reduces computation time, since not all of the connections have to be determined. The result will differ from the result of a full search, and the quality of the results depends on the transport supply side. The limitation takes less effect in case of regular, fixed-rhythm headway service compared to networks with few, irregular services. The correct calculation of the service frequency is only possible if all times of departure are considered. For limited search, option Reverse correction is recommended. |
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Reverse correction |
If this option has been checked, a reverse search based on the arrival time at the destination stop in the destination zone is conducted to find a later departure either of the same line or of a different line for every part of the found connection. This reduces journey and transfer times. In this way, a better connection with identical stop points (origin, all transfer stop points, destination) for the calculated arrival time may be found which has a later departure time. Instead of the initially found connection, the connection detected by reverse correction will be used. |
Specifying TSys-specific impedances
In this window, you define - by transport system - the supplement to be added to the impedance.
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Element |
Description |
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Imp/km |
The TSys-specific fare/km is multiplied by the total number of km covered in the TSys. |
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Imp/fare point |
The TSys-specific fare/FP is multiplied by the total number of fare points on links traversed in the TSys. |
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Imp/TSys-AddVal |
The TSys-specific value is multiplied by the total TSys-AddVal of the links traversed in the TSys. |
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Const. supplem. |
The constant supplement is considered once for the entire connection. |
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Const. supplem. per path leg |
The constant supplement is considered for each path leg covered in the transport system. |
Specifying vehicle journey-specific impedances
In this window, you define - by vehicle journey - the supplement to be added to the impedance.
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Element |
Description |
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Boarding supplement |
Select a direct or indirect numerical vehicle journey attribute of the vehicle journey course which is to be used as boarding supplement. The boarding supplement is charged on each PuT path leg for the first vehicle journey item of this path leg. Note Attribute values < 0 are regarded as if = 0. |
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Discomfort supplement |
Select a direct or indirect numerical vehicle journey attribute of the vehicle journey course which is to be used as boarding supplement. The discomfort supplement is charged for all items between the first vehicle journey item (included) of the path leg and the last vehicle journey item of the path leg (excluded) and will be aggregated according to the user's choice. The last item does not count, since in this context the „link view“ on the vehicle journey is applied, which means the transport from one stop to the next. Transport is not continued after passing the last item. Note Attribute values < 0 are regarded as if = 0. |
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Aggregate function |
In the selection list, select the appropriate aggregate function:
This function aggregates the values per vehicle journey item to determine the value by path leg. Note If the weighted mean is used for aggregation, another vehicle journey item attribute can be selected for weighting. |
