PTV VISUM 12.5 NEW FEATURES AT A GLANCE

Transcription

1 PTV VISUM 12.5 NEW FEATURES AT A GLANCE

2 Copyright: 2012 PTV AG, Karlsruhe PTV Visum is a trademark of PTV AG All brand or product names in this documentation are trademarks or registered trademarks of the corresponding companies or organizations. All rights reserved. Disclaimer: The information contained in this document is subject to change without notice and should not be construed as a commitment on the part of the vendor. This document may not be used for any other purpose than the personal use of the purchaser. No part of this handbook may be reproduced, stored in a retrieval system, or transmitted, in any form, or by any means, electronic, mechanical, photocopying, recording, or otherwise, edited or translated, except as permitted under the terms of the copyright, without the prior written permission of PTV AG. Impressum: PTV AG Traffic Software Haid-und-Neu-Straße 15 D Karlsruhe Germany Phone Fax info.vision@ptv.de PTV AG, Karlsruhe 2

3 Contents 1 Windows redesign 4 2 Public transport assignments Timetable-based: capacity restrained assignment Headway-based assignment using the fare model 7 3 Private Transport LUCE PrT assignment report Diagnosis output for TFlowFuzzy 10 4 Graphics Bing aerial images as background Classified display 12 5 Better display of public transport supply Schematic line diagram Transfer relations Graphical display of PuT transfer connections at a stop 15 6 Demand calculation Nested demand model Multi-threading for VISEM calculation Dialogs for demand model operations 18 7 Interfaces Open street map import railml import and export 20 8 COM MapMatcher 21 Visum New features at a glance PTV AG 3

4 Windows redesign 1 Windows redesign When working with Visum it is often difficult to align all views and tool windows within the Visum frame window. This means that frequent changes between open views are necessary to obtain information about the data. Furthermore, it is common today to work on more than one monitor. The restriction to the Visum frame window does not support this possibility adequately. This fact was the main motivation behind the redesign of the handling of windows in Visum. Other aspects of usability have been improved too in order to reduce the need to change between views and toolbars to access icons linked to a certain functionality. The main advantage is that views such as lists, editors, or the procedure dialog, can be moved outside the Visum frame window. Views can be arranged in several ways. New options are offered by docking views in the same windows, e.g. horizonatally, vertically or also in tabs. These options are supported visually, i.e. the user can easily configure windows that best support the task at hand. The three integral parts of the former tool window Overview can now be moved and arranged individually, so that any mouse click required to change between Net, Marking and Matrices becomes redundant. The network window can now be closed as any other view. 4 Visum New features at a glance PTV AG

5 Windows redesign Toolbars have also been rearranged. The new concept focuses on required functionality in different views. The Visum frame window only contains icons for functionality with a global reference. Views have a local toolbar which for example already existed in lists. In the network window a new toolbar is added which includes functionality for graphics, zoom options, printing etc. Visum New features at a glance PTV AG 5

6 Windows redesign 6 Visum New features at a glance PTV AG

7 Public transport assignments 2 Public transport assignments 2.1 Timetable-based: capacity restrained assignment In general, ignoring capacity constraints in public transport assignments is a simplification which does not reflect reality in highly utilized PuT systems. To account for this deficiency a new option for the timetable-based assignment has been introduced which allows to investigate the effects of capacity constraints. Consequently, the parameters for the timetablebased assignment are extended to reflect additional options for capacity constraints. Taking capacity constraints into account can already affect the search of connections. For example, considering also the demand side during the search means that due to their volume-capacity ratio some connections can become attractive alternatives. For that reason, the capacity constrained assignment includes an optional second search which ensures that the set of connections also includes vehicle journeys with low volume-capacity ratios. The procedure then is based on an iterative approach in which passenger volumes and impedances are balanced. The impedance includes a volume-capacity ratio based component which can be calculated based on different options. All these options have in common that this impedance component is a continuously increasing function of the volumecapacity ratio. To avoid oscillations between higly utilized connections one can optionally smooth impedances or volume-capacity ratios. This usually forces the procedure to converge. Generally, capacity constraints in this context resemble the effects of crowding as an inconvenience for passengers on board. This discomfort on board may be perceived as one of the aspects with the greatest practical impact. Capacity restraint Public Transport assignment is not multithreaded yet. 2.2 Headway-based assignment using the fare model In the impedance definition for the headway-based assignment, we have added an addi- Visum New features at a glance PTV AG 7

8 Public transport assignments tional option that allows the use of fares alternative to fare points. The fares are based on the fare model and calculated for each path leg. Start and transfer fares are correctly applied. Consequently, this option allows you to take complex fare structures e.g. zone-based fares in the headway-based assignment into account. For complex fare models run times of the assignment can be higher compared to the use of fare points as component in the impedance. 8 Visum New features at a glance PTV AG

9 Private Transport 3 Private Transport 3.1 LUCE Based on our experience with the LUCE assignment method we have further improved the efficiency of the algorithm. The basic principle is unchanged, i.e. volumes are saved in bushes and all paths from an origin are balanced simultaneously. The changes concern the actual implementation. We now eliminate a great number of shortest path searches which makes the algorithm much faster in particular on big networks. The numerical implementation of the balancing step has been revised resulting in more robustness against steep volume delay functions (VDFs) or those with step changes. Nevertheless, VDFs with such properties slow down convergence. The improvements will change the assignment result. Concerning performance issues, it must be mentioned that the changes in the implementation also enable multi-threading of the algorithm. This is an important step because, unlike in the case of MSA methods such as Lohse assignment, no efficient methods for multithreading highly-convergent assignment algorithms were known. Two particularities are noted: Firstly, our tests with a number of networks have shown that often the maximum speed of the assignment is reached when using 3-4 cores even if more cores are available on the machine. If more cores are used then there are conflicts during balancing between the cores so that the calculation speed decreases. As a consequence, it is now possible to define the number of cores locally in the parameters of the procedure. These settings override the global settings under menu Extras -> Options. Secondly, because of interactions between cores calculation results can only be reproduced if the same number of cores is used. This is in contrast to all other procedures in Visum where calculation results can always be reproduced. This makes the local parameter even more important because users can ensure that results are reproducible. The deviation of results for different numbers of cores can be minimized if a sufficient small gap Visum New features at a glance PTV AG 9

10 Private Transport value (e.g. smaller than 10-6 ) for the termination criterion is defined. 3.2 PrT assignment report The PrT assignment report automatically generates a summary of assignment results which are saved to an excel file. Optionally a PDF report can be created. The use of templates allows to add individual components to the report. The assignment report is generated by an Add-in which is linked to a PrT assignment in the procedure dialog. The parameters of the Add-in allow to design each output individually. The report is divided into two parts: assignment statistics calculation results The statistics include the input parameters such as assignment method, target gap, minimum number of iterations as well as the output statistics. An overview of the most important network indicators among them total vehicle-hours and total vehicle-km is provided. Optionally, results per iteration and graphs can be added. The contents of the second part, the calculation results, can be defined individually. The parameter dialog allows to select attributes of corresponding network objects (e.g. links, screenlines, nodes) of which aggregated values such as minimum, maximum, average, sum are reported. Additionally, each attribute can be grouped depending on a second attribute. A typical example is for links the speed grouped by the global link type. For grouped outputs graphs can be produced too. 3.3 Diagnosis output for TFlowFuzzy The procedure TFlowFuzzy optionally generates additional diognostic outputs, which can assist in particular when the procedure does not find a solution. The Visum log file contains different types of analyses, among them one that reports potential conflicts between count values. Typically, conflicts can arise when count values of neighboring objects provide contradictory data. The additional output of GEH values for other analyses are helpful for trou- 10 Visum New features at a glance PTV AG

11 Private Transport bleshooting. In particular, objects with high GEH values should be examined further. Moreover the count location causing the conflict that leads to the termination of the procedure is identified. A separate statistics file documenting the trend the fitted count data, the GEH values between fitted versus count values and the trend of relative deviations of demand matrix values over the iterations can be saved. Visum New features at a glance PTV AG 11

12 Graphics 4 Graphics 4.1 Bing aerial images as background Visum 12 introduced a feature allowing to automatically download map renderings provided by OpenStreetMap and use them as background imagery for network models. For our customers with a service contract, we have extended this functionality to also allow using aerial imagery provided by Bing Maps, offering high detail e.g. for junction layouts. 4.2 Classified display The user interfaces for setting the graphics parameters for the classified display of point and polygon objects have been modernized. Similar to the user interface for link bars, the new dialog organizes the most important parameters in a configurable grid control which allows for copy&paste and simultaneous editing of multiple entries. A graphical preview provides immediate feedback on all changes and modern sub-dialogs allow the quick adaptation of the classification scheme, number and bounds of classes, colors and symbol sizes. 12 Visum New features at a glance PTV AG

13 Graphics Visum New features at a glance PTV AG 13

14 Better display of public transport supply 5 Better display of public transport supply 5.1 Schematic line diagram The add-on module timetable-network-graph now named Schematic line diagram has been completely revised and now features a much more flexible and configurable display and new functionality. The schematic line diagram is used to generate a schematic illustration of the PuT supply. Stops are displayed as boxes with positions usually roughly matching their geographic relations. These stops are connected by graph edges which indicate the presence of a set of vehicle journeys matching a given criterion or classification between these stops. The selections and classifications can be defined with respect to different aspects such as line, transport system, operator, service trip pattern etc. The stop positions and routing of edges are initially determined automatically, but allow for manual editing and later automatic optimization. Extensive graphics parameters and labeling options allow the illustration of different attributes, e.g. as classified graphical bars or as text labels. Additionally, transfer flows can be visualized as bars within the stop nodes. Like all views in Visum, the schematic line diagram is fully synchronized, all changes to attributes are immediately reflected in the display and markings are shown in other windows as well, e.g. the network editor. All graphic parameters and settings for the positioning of nodes, routing of edges and aggregation levels of vehicle journeys can be stored in separate files and thereby easily applied e.g. to alternative or updated versions of the schedule. Visum keeps track of the manual modifications - e.g. for routing of edges even when these elements are temporally removed from the display due to changes to the data. The settings are restored when these elements are added again to the display. 14 Visum New features at a glance PTV AG

15 Better display of public transport supply 5.2 Transfer relations The introduction of the new graphics layer Transfer relations allows the display of volume bars for transfer flows between stop areas in the network. The display is required in networks in which the stop hierarchy has been used to realistically model transfers at important stops or stations. Equally, other attributes like different walk times can graphically be displayed. Up to now, these data could be extracted from the corresponding list. The corresponding list Transfers and stop area walk times in stop has been adapted. Compared to the previous version the list now shows all pairs of stop areas with all the information in one row. This means that transfer flows, walk times and flow bundle results are more clearly arranged in the tabular view. 5.3 Graphical display of PuT transfer connections at a stop The evaluation of connections in PuT networks is an important task. For a more detailed assessment both the supply and demand side must be taken into account. For example, the planner might need to test how the temporal shift of vehicle journeys affects the quality of transfer connections at important stops in the network. Corresponding scenarios require to quantify the improvements for passengers as well as their costs on the supply side, for example by changes of line blocks and number of vehicles. The new view of PuT connections presents a compact display of such dependencies within a stop. On the supply side, all vehicle journeys arriving and departing at the stop are shown. The demand side is represented by volume bars of the vehicle journeys and by the transfer flows within the stop. Visum New features at a glance PTV AG 15

16 Better display of public transport supply The view is displayed as a clockface with the time scale defined by the basic cycle, typically a multiple of 60min. Around the outer edge of the clock arriving and departing vehicle journeys are shown at the minute they pass the stop. Within pre-defined tolerance ranges vehicle journeys can optionally be aggregated into service groups allowing also a corresponding display of passenger volumes and transfer flows. Transfer flows within the stop are shown in the inner part of the clock. Additionally, transfer and walk times are available at the edge of the clock for marked pairs of arriving and departing vehicle journeys or service groups, respectively. Furthermore, the view also allows editing of the supply side. More specifically, vehicle journeys can be shifted to easily evaluate scenarios with different arrival and departure times and their effects for connections. The latter can also be observed for other stops at the same time because multiple views can be opened and their display is always synchronized in the network. Any changes to the supply would require a new assignment. Yet, in the view the current display is maintained with an additional hint that results are not up-to-date. 16 Visum New features at a glance PTV AG

17 Demand calculation 6 Demand calculation 6.1 Nested demand model The Nested Demand Model represents an improved version of the standard 4-step model for demand calculation. This development is mainly driven by country-specific requests, but also by existing restrictions in our existing 4-step approach. The calculation is based on a nested logit approach which requires the definition of model structures for each of the demand strata. The following example shows a model structure that includes destination choice (D) at the bottom level, and then macro time period (T) and mode choice (M) going the hierarchy towards the top level. Mode choice itself is nested with the choice between motorized versus bike at the highest level. The labels at the arrows represent alternatives of the corresponding choices, e.g. AM, Interpeak (IP) and PM for macro time period choice. The Nested Demand Model is an Add-in which can be applied in the procedures. It contains a number of advantages compared to the standard 4-step model: Choices can include destination, mode, and macro time period choice. The choices can appear in any sequence. Mode choice itself can be nested. Logsums are calculated and carried up in the hierarchy starting from the bottom level to the top level. Optionally the user can choose to output logsums by level and model structure. The model can be run in absolute (synthesis from scratch) or incremental (pivot point) mode. Destination choice can be singly or doubly-constrained. For doubly-constrained, multiple demand strata (e.g. different person groups with the same trip purpose) can compete for the same attraction (e.g. jobs), i.e. exhaust them collectively. The model can be run in PA (Production/Attraction), i.e. the resulting matrices represent round trips, or OD (Origin/Destination) form (single trips). Destination choice can be calculated using a gravity model instead of the logit formulation. This option is only available if D represents the top level in the model structure. Visum New features at a glance PTV AG 17

18 Demand calculation Like for the 4-step model the Add-in requires the definition of a demand model in the Visum version, but parameters can simply be defined in an excel file. In contrast to the built-in demand models, all corresponding matrices are referenced by using user-defined attributes of matrices. 6.2 Multi-threading for VISEM calculation Over recent release versions we enabled the parallization of different operations to allow better use of multi core processors. For demand calculations corresponding improvements have been reported in Visum 12 for the operations EVA weighting and EVA distribution/mode choice. Now the combined distribution and mode choice of the tour-based demand calculation (VISEM) is also multi-threaded. First tests with medium-sized to large models suggest that the speed-up factor is slightly above the number of cores. Due to the fact that demand models are usually run in feedback loops the potential for time savings is considerable. Further savings can be achieved in models with several VISEM-procedures one after the other for the caculation of matrices of different time intervals. With Visum 12.5 it is now possible to define unlimited number of output matrices with any combination of person group, modes, activities and time intervals within a single VISEM run. 6.3 Dialogs for demand model operations Dialogs in connection with different steps of the demand models have been redesigned in order to make the structure clearer and more uniform. To achieve a better usability with a reduced number of clicks for large numbers of demand strata, whilst functions have not changed, dialogs have been modified for the following demand models: Standard 4-step EVA-P Tour-based model The structure of the new dialogs is similar over all demand models as well as the steps within each demand model. Basic idea of the new dialogs is to arrange the demand strata with all details as a list. This makes it easier to compare entries for different demand strata and to spot possible errors. The image below is an example for the trip distribution dialog in a 4-step model. Each row represents one demand stratum with all related details. Here they are the composition of utility function, the type of deterrence function with parameters a, b and c and direction parameters. 18 Visum New features at a glance PTV AG

19 Demand calculation Entries of one demand stratum can be applied to all other demand strata. All white fields can be edited directly, grey fields must be edited with a separate sub-dialog or cannot be edited. White fields also have a copy&paste functionality. Utility functions can be composed by a combination of matrix values, zone attributes (origin or destination) and a constant value. The different components are indicated in different colors. Each sub-dialog allows to switch between the different demand strata. Visum New features at a glance PTV AG 19

20 Interfaces 7 Interfaces 7.1 Open street map import In addition to using pre-rendered maps from OpenStreetMap as background graphics, a new importer allows to import OpenStreetMap data as network objects and to create or extend a transportation model using this data. The rich contents of OpenStreetMap data is filtered, classified, adapted to the (topological) requirements of the Visum data model and converted to the Visum format. In addition to the geographical layout of nodes and links of the network, additional attributes such as one-way street, link type, vehicle type restrictions, turn restrictions are being extracted from the original data when available and imported into the Visum model. The workflow can be controlled through configuration files, allowing to adapt the results to country-specific regulations or to a custom link classification scheme. 7.2 railml import and export The import of railml data has already been added in Visum 12. The railml -standard is directed towards railway organizations and includes related aspects such as timetable, infrastructure, rolling stock, control and safety technology etc. The import to Visum focuses on timetable data. Other data are only imported if they are required for time tables. Timetable data and basic information on vehicle usage are imported into an existing PuT network by matching the corresponding elements (stops etc.) through their IDs. The interface supports railml data in format 2.0 or 2.1 The railml export generates a xml file in line with railml -standard version 2.1. The file contains network and time table data as well as information about the rolling stock, i.e. only the schemes infrastructure, rollingstock, and timetable are written. 20 Visum New features at a glance PTV AG

21 COM MapMatcher 8 COM MapMatcher The COM-interface of Visum 12.5 offers a new functionality which facilitates the development of custom importers for external data. Visum offers a MapMatcher-object which can be controlled through COM and provides methods for matching sequences of geographic point locations e.g. representing the course of PuT lines, GPS positions of floating cars or edges of a road network to the links and nodes of the network loaded in Visum. External information can then be associated with the best matching objects and thereby be transferred to the Visum network model. Visum New features at a glance PTV AG 21

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