Important changes compared to previous versions

The behavior of Vissim is significantly different to that of previous versions, particularly when accounting for the following changes and new features.

You can find a complete list of the new features and changes to the current version in your Vissim installation in the directory ..\Doc\<language ID> in the file ReleaseNotes_Vissim_<language ID>.pdf

Changes in Vissim 2024 compared to Vissim 2023

The details of the modifications are outlined in the document titled Vissim 2024 - What's New.pdf. By default, you can locate this document in your Vissim installation directory under "..\Doc<language abbreviation>."

Note: 3D models in the format *.v3d are saved to the installation directory ..\Exe\3DModels\_Legacy up until Vissim 2024. This directory will no longer be available from Vissim 2025. If you need 3D models in the *.v3d file format from Vissim 2025, simply copy the necessary files from a prior version of Vissim 2025 to your preferred data directory.
Changes compared to versions prior to Vissim 2023 (SP4)

Vehicle simulation: Vehicles required to yield at crossing conflict areas, which allow blocking of the major flow, also use the option to block the major flow if they cannot leave the conflict area because there is not enough space downstream. As a result, simulation results in Vissim networks may differ from those of previous versions.

Changes compared to versions prior to Vissim 2023 (SP3)
  • Vehicle simulation: Vehicles now react better to lane conflicts in neighboring lane sections and to other vehicles approaching or being involved in these lane conflicts. For example, vehicles now more reliably keep conflicts unblocked. As a result, simulation results in Vissim networks with intersections managed by conflict areas may differ from those of previous versions.
  • Vehicle simulation: Vehicles take into account their maximum achievable speed when planning lane changes and overtaking maneuvers. This is defined by the maximum acceleration and desired acceleration functions as well as by the current gradient at the position of the vehicle. As a result, simulation results in Vissim networks may differ from those of previous versions.
  • Vehicle simulation: Vehicles take their curve speed into account when planning lane changes and overtaking maneuvers. As a result, simulation results in Vissim networks with enabled speed limitation in curves may differ from those of previous versions.
  • Vehicle simulation: Vehicles that repeatedly park and unpark drive more reliably back to their original route after unparking. As a result, simulation results in Vissim networks may differ from those of previous versions.
Changes compared to versions prior to Vissim 2023 (SP2)

Vehicle simulation: Simulation results in Vissim networks may differ from those of previous versions:

  • In Vissim networks with vehicles approaching multiple conflict areas. The vehicles’ driving behavior is based on the vehicle following model No interaction.
  • In Vissim networks with vehicles for which the option Diamond queuing is selected as driving behavior as part of their lateral behavior.
  • Timing may change where vehicle types of the Pedestrian category are used at vehicle inputs.
  • Vehicles now no longer ignore other vehicles that are in the process of parking in reverse in certain situations.
Changes compared to versions prior to Vissim 2023 (SP1)
  • Importing models from Synchro is no longer supported. Instead, use PTV Vistro. PTV Vistro offers convenient functions for importing and editing models from Synchro.
  • Vehicle simulation: Vehicles approaching conflict areas now also react to vehicles in front whose vehicle rear is still in the conflict area, even if the vehicle in front leaves the conflict area via an outgoing connector. As a result, simulation results in Vissim networks with intersections managed by conflict areas may differ from those of earlier versions.
Changes compared to versions prior to Vissim 2022 (SP 08)

Vehicle simulation: Vehicles estimate the distance to the vehicle in front correctly more often when several vehicles close up in the same or an adjacent lane. As a result, simulation results in Vissim networks may differ from those of previous versions.

Changes compared to versions prior to Vissim 2022 (SP 07)

Vehicle simulation: An issue where parking vehicles obstructed each other has been solved. As a result, simulation results in Vissim networks with vehicles parking in reverse may differ from those of earlier versions.

Changes compared to versions prior to Vissim 2022 (SP 06)

Evaluations: Emissions calculated by Bosch are now mapped more accurately to route segments. As a result, simulation results may differ from those of previous versions.

Changes compared to versions prior to Vissim 2022 (SP 05)

Vehicle simulation:

  • In networks with stop signs and parking routing decisions, where the Full occupancy behavior attribute has the value Wait, vehicles can no longer block each other. As a result, simulation results may differ from those of previous versions.
  • In networks where parking lots are used for backing out, results in the vehicle network performance may differ from those of previous versions.
  • In networks where vehicles miss their parking space or stop, simulation results may differ from those of previous versions.
  • The jerk limitation no longer applies to vehicles driving backwards. Simulation results may differ from those of previous versions.
Changes compared to versions prior to Vissim 2022 (SP 04)

Dynamic assignment: Vehicles may behave differently on conflict areas compared to previous versions if they take into account the route of other vehicles.

Vehicle simulation:

  • The driving behavior of vehicles differs from previous versions when the vehicle type is changed during a lane change.
  • Simulation results may differ from those of previous versions if the network contains static vehicle routing decisions that are not valid for all vehicle classes and for which the Combine static routing decisions attribute is active.
Changes compared to versions prior to Vissim 2022 (SP 03)

Viswalk: Minor changes in pedestrian behavior may occur. Pedestrians walk slightly different paths, especially near walls and obstacles.

Changes compared to versions prior to Vissim 2022 (SP 01)

Vehicle simulation: The interaction of lane changes, overtaking on the same lane as well as observing adjacent lanes have been improved. This means that vehicles are less likely to block each other when changing lanes. Simulation results may differ from those of previous versions if vehicles are next to each other on the same lane (or have crashed into each other) and want to change lanes.

Evaluations: The delay of a reversing vehicle is now always zero. Vissim networks with reversing vehicles may have changed delay results compared to previous versions.

Evaluations: Negative delay of vehicles is prevented in every time step and in the correction calculation for reduced speed areas. Vehicles may have changed delay results compared to previous versions.

Changes compared to versions prior to Vissim 2021 (SP 09)

Vehicle simulation: The speed and acceleration of the vehicles within a platoon are interpolated between the lead vehicle and the last vehicle. Simulation results in networks with platooning may differ from those of previous versions.

Changes compared to versions prior to Vissim 2021 (SP 07)

Mesoscopic simulation: if the lane change distance of a downstream connector extends back into a meso edge, meso vehicles already consider their lane preferences on all meso edges up to that link when selecting a lane for that edge (in its exit node). This can lead to changed simulation results compared to previous versions.

Changes compared to versions prior to Vissim 2021 (SP 06)

Mesoscopic simulation: New attribute Meso penalty (merging vehicles): If there are driving behaviors with different meso reaction times, this can lead to changed simulation results compared to previous versions.

Changes compared to versions prior to Vissim 2021 (SP 04)

Mesoscopic simulation: The link segment evaluation is performed according to a new calculation method. This is more accurate, especially with low volumes. This can lead to changed results in link segment evaluation compared to previous versions.

Changes compared to versions prior to Vissim 2021 (SP 03)
  • Pedestrian simulation:
  • Obstacles and parts of areas which are less than the grid cell size can lead to changed simulation results compared to previous versions.
  • Pedestrians that are newly inserted into the network and whose route leads directly to a queue or a waiting area with no pedestrians in the queue move towards the end of the queue or towards the waiting area from the first time step. This can lead to different simulation results of queues, public transport vehicles and elevators compared to previous versions.
  • Vehicle simulation: Parking lots with vehicles backing out of the parking lot onto a link with multiple lanes can lead to changed simulation results compared to previous versions.
Changes compared to versions prior to Vissim 2021 (SP 02)
  • File management: Special characters are now encoded in UTF-8 in almost all text output files. In some of these files BOM is written at the beginning.
  • ANM import: If there are multiple class-specific desired speeds in the ANM file that differ by less than 0.1 km/h, the network created during import may differ from the network in previous versions.
Changes compared to versions prior to Vissim 2021 (SP 01)
  • Pedestrian simulation:
  • Grid cells that are only partially on areas or ramps, or are partially occupied by obstacles, are no longer considered walkable ground. This can lead to changed simulation results compared to previous versions.
  • The detection of grid cells on ramps has been changed. Results of pedestrian grid cell evaluation on ramps may differ from previous versions.
Changes compared to versions prior to Vissim 2021 (SP 00)

DriverModel.DLL interface: The Exe\DriverModelData\ subdirectory is no longer needed. The absolute path to this subdirectory is no longer passed to the DLL. A DLL that expects to be passed the path to this subdirectory might no longer work.

Changes compared to versions prior to Vissim 2020 (SP 09)

Vehicle simulation: For result attributes that contain data from routes or platooning, the vehicle record displays values for the end of the time step, i.e. for when the vehicle has traversed the marker of a routing decision and/or, if applicable, the lead vehicle of a platoon has left the Vissim network. This can lead to different route attribute and platooning attribute values compared to previous versions.

Changes compared to versions prior to Vissim 2020 (SP 08)

Vehicle simulation: Driving behavior for which the attribute Observe adjacent lanes is selected can lead to simulation results that differ from those of previous versions. The vehicle no longer moves as far to the left as possible in situations where the minimum lateral distance to vehicles on both adjacent lanes cannot be maintained at the same time.

Changes compared to versions prior to Vissim 2020 (SP 04)

Mesoscopic simulation: Sections you select for microsimulation include the links and connectors on their level. Thus, when you are dealing with connectors that connect on two different levels you might receive different simulation results than with previous versions.

Changes compared to versions prior to Vissim 2020 (SP 03)

In vehicle simulation, the following properties or conditions can lead to simulation results that differ from those of previous versions:

  • when vehicles travel at a desired speed of less than or equal to 0.1 m/s on multi-lane links
  • in networks with conflict areas on multi-lane links: conflict areas are no longer counted when counting the interaction objects on the adjacent lane.
  • A conflict area affects the vehicle when it leaves its link within the conflict area via a connector.
  • Faster initialization and higher simulation speed in networks with parking lots from which vehicles can back out of.
Changes compared to versions prior to Vissim 2020 (SP 02)
  • Vehicle simulation: Using networks with parking lots from which vehicles can back out of can lead to changed simulation results compared to previous versions.
  • Data model: The unit of some z-coordinate attributes corresponds to the short length unit selected in the network settings (m or ft). This is why COM scripts that access attributes for z-coordinates may produce different results than with previous versions.
Changes compared to versions prior to 2020 (SP 01)
  • Mesoscopic simulation: Signal groups with amber-red can lead to different simulation results than obtained with previous versions.
  • Vehicle simulation:
  • Parking lots where vehicles can back out of the parking lot which have multiple incoming connectors can lead to different simulation results than obtained with previous versions.
  • Vehicles backing out of parking spaces now stop a little earlier for a change of direction.
Changes compared to versions prior to Vissim 2020 (SP 00)
  • Network evaluation: Changes to the meso graph can lead to different results in the last decimal places compared to in previous versions.
  • Driving behavior parameters for following: The attribute Standstill distance for static obstacles has a minimum value of 0.01 m.
  • Vehicle simulation: Simulation runs may have changed results compared to previous versions if the maximum speed of a vehicle on a multi-lane link falls below its desired speed, for example on a gradient.
  • Vissim can usually also be run on most other versions of the Microsoft Windows operating system than those specified in the system requirements, as long as they are currently supported by Microsoft (see  Windows lifecycle fact sheet). System requirements for Vissim can be found on our webpage  System requirements for the PTV Vision Software products.
Changes compared to versions prior to Vissim 11.00-00

In pedestrian simulation, simulation results may differ from previous versions:

  • If there is a waiting area for which the waiting position approach method Potential is selected, and if the route to that waiting area uses dynamic potential.
  • If the attributes Cell size or Obstacle distance of areas, ramps or stairs have more than four decimal places in metric units, or non-standard values in imperial units.
Changes compared to versions prior to Vissim 11.00-08

With dynamic assignment, evaluation results for the direct output Convergence in Vissim networks with locked edges may differ from those of previous versions.

Changes compared to versions prior to Vissim 11.00-07
  • Paths for zero-volume OD pairs can be dealt with differently than in previous versions (Attributes for path search).
  • Evaluations: Delays in node evaluation may differ from those in previous versions if there are parking lots in the Vissim network that have not been assigned a zone.
Changes compared to versions prior to Vissim 11.00-05

Vehicle attribute decisions are defined for each lane and no longer across all lanes of a link (Using vehicle attribute decisions).

Changes compared to versions after Vissim 11.00-00 and prior to 11.00-05

Vehicle simulation: Conflict areas between two links are treated as a merging conflict type, if connectors lead from both links to one joint link. Conflict areas between two links are treated as a branching conflict, if both links have connectors that stem from the same link.

Changes compared to versions prior to Vissim 11.00-04

Pedestrian simulation:

  • Individual pedestrians no longer block each other at the beginning of a queue. Therefore, networks with queues may lead to different results than in previous versions.
  • The number of pedestrians no longer builds up at the bottom of an escalator in certain situations. Therefore, networks with escalators may lead to different results compared to previous versions.
Changes compared to versions prior to Vissim 11.00-02

Vehicle simulation: In the Driving Behavior window, the Smooth closeup behavior option is removed. Smooth closeup behavior is enabled for all vehicles by default. You can no longer access the setting via the user interface or the COM interface. A network file from a version prior to 11.00-02, in which the Smooth closeup behavior option is not selected, can be opened in version 11.00-02 and higher. In this case, the option is ignored.

Changes compared to versions prior to Vissim 11.00-01
  • The percentage of convergence in the convergence evaluation may also differ from the one in previous versions (Saving data about the convergence of the dynamic assignment to a file).
  • Viswalk: Non-reproducible behavior in queues has been fixed. The behavior of is significantly different to that of previous versions, particularly when accounting for the following changes and new features.
Changes compared to versions prior to Vissim 11
  • Previous versions of Vissim are available in both 32-bit and 64-bit editions.

Vissim 11 is available as a 64-bit edition only.

  • This means that to use Vissim 11, you will need to use a 64-bit operating system.
  • If you are applying a 32-bit control procedure in Vissim 11, contact the provider of the respective control procedure and ask for a 64-bit version of the same. The DLL files of control procedures that are provided with PTV GROUP are available in a 64-bit version.
  • Vehicle simulation: The vehicle attributes Minimum clearance, Leading target type and Leading target number may show different values than in previous versions if vehicles are controlled via the COM interface or the driving simulator interface.
  • Vehicle simulation: The predefined and user-defined attribute of routing decisions UseVehRouteNo and that of vehicles NextRouteNo no longer have a specific effect during the simulation run. Their functionality in Vissim 10 has been replaced by the route choice method Formula (Attributes of static vehicle routes).
Changes compared to versions prior to Vissim 10

In versions prior to Vissim 10, the Discontinued models directory is installed in the installation directory of Vissim, under ..\Exe\3DModels\Vehicles and ..\Exe\3DModels\Pedestrians.

From Vissim 10, the Discontinued models directory is no longer installed. To use 3D models of this directory in Vissim 10, save the 3D models of the version prior to Vissim 10. Then after installing Vissim 10, copy them into the directory where the *.inpx file is saved.

Changes compared to versions prior to Vissim 9.00-03

In previous versions of Vissim 9.00-03, a route location on a ramp or stairway has no direction defined for its use by pedestrians. From Vissim 9.00-03, a route location defines a direction for several cases (Modeling the course of pedestrian routes using intermediate points).

Changes compared to versions prior to Vissim 9
  • In versions prior to Vissim 9, the origin-destination matrix for dynamic assignment is saved to *.fma file. From Vissim 9 on, the origin-destination matrix is saved to a matrix in Vissim, it can be shown in the Matrices list and edited in the matrix editor.
  • To access the Help in versions prior to Vissim 9, on the Help menu, click > PTV Vissim Help. From Vissim 9, you can show the Help page (including attribute descriptions) for some windows. To do so, in the respective window, press the F1 button or click the ? button.
Changes compared to versions prior to Vissim 8.00-14 and Vissim 9.00-03

In previous versions of Vissim, selecting the path pre-selection options Reject paths with too high total cost and Limit number of paths meant that paths were deleted from the path collection/path file. From Vissim 8.00-14 and Vissim 9.00-03, selecting these options only means that the corresponding paths will not be used in the respective time interval.

Changes compared to versions prior to Vissim 8
  • In previous versions of Viswalk, for pedestrians, you could select Never walk back. This attribute is no longer available. If the attribute is still activated in older entry data, the attribute is deactivated when imported.
  • In previous versions, licenses could not be managed within Vissim. This is now possible from Vissim 8 (PTV Vision License Management). The simulation results of Vissim 7 and Vissim 8 may differ, as e.g. the departure times from vehicle inputs, parking lots and of PT lines were made uniform and for some special cases, an improved driving behavior was integrated.
Changes compared to versions prior to Vissim 7

Superordinate topic:

Basics