VISSIM FAQ

Where can I find the new features and differences between two VISSIM versions?  (#99)

This information is contained in the release notes file that is contained in every VISSIM installation and service pack. It can also be viewed on our website in the service pack download area by pressing "view" in the column "Release Notes" (login required - see FAQ #77).

Does VISSIM run on 64-bit operating systems such as Windows® Vista® 64?  (#86)

Yes, if the latest version of the hardlock driver is installed. Yet the current VISSIM version cannot use more than 2 GB of RAM under standard conditions. This will be possible only with a 64-bit version of VISSIM which will be available in the future. However, 64-bit is only an issue for networks which don't fit inside 2 GB.

Where can I find MULTI.EXE which was provided in earlier VISSIM versions?  (#78)

The functionality of MULTI.EXE has been included directly in the program at "Simulation - Multirun...". In addition (and for earlier VISSIM versions) an Excel® COM script with the MULTI functionality is included in the standard installation at \Example\Training\COM\Multi

Which graphics card has the best performance with VISSIM 3D? (#6)

Best results are achieved with graphics cards using nVidia® Geforce® chipsets. In history we've experienced some problems with ATI® chipsets as some graphics funtionality was done through software rather than hardware. In general the most important thing is full compatibility with OpenGL®. In order to find out if a graphics card has this feature you could check graphics cards test reports which show the behavior and speed when running OpenGL® applications.
A lot of graphics RAM is important if you have a 3D scene highly loaded with textures. For standard 3D applications 64 MB of graphics RAM are sufficient. It is also important to use the latest graphics driver.
If in doubt, try it out (e.g. with a VISSIM demo version).

I've installed VISSIM on a server and placed the network dongle in one of the USB slots. When I try to run VISSIM from any client, I get the error message "Application could not be initialized." What could be the problem?  (#5)

Please check the following points:

• Is the necessary version of the Microsoft® .NET framework installed on all clients? (see VISSIM manual for .NET Framework version information)
• Do the clients have write access to the VISSIM/exe directory on the server?
• In the "local intranet" settings of each client, is "Full trust" activated? To find this setting, go to "Control Panel" - "Administrative Tools" and select the Microsoft® .NET Framework Wizards. Choose "Adjust .net security" - "Change settings for this computer" - "Next" - "local intranet" and move the slider to "full trust". Confirm with "Next" - "Finish".

When trying to run VISSIM, I get this message: "Runtime error: This VISSIM version has expired." What do I have to do? (#4)

This message indicates that the expiry date of your VISSIM version is reached (e.g. in a lease, demo or test version). If you feel that you get this message in error, please contact our customer service.

What are the hardware and software requirements for VISSIM? (#3)

In addition to the typical specifications of a common PC, these are the main requirements for the current VISSIM version:

Operating system:

• At least Microsoft® Windows® Vista, XP or 2000
• Microsoft® .NET Framework 2.0 (language independent installation setup is included in the VISSIM installation package)

Hardware:

• Speed: min. 2 GHz (faster computer speed results in faster simulation speed)
• Memory (RAM): min. 1GB (2GB for Windows® Vista)
• Hard disk space: depending on the installation settings up to 500 MB
• Hardlock protection: one fully functional USB port
• Graphics card: for 3D Graphics OpenGL®-support is essential. For details please check FAQ #6.
• Multi-core processors are recommended if other tasks are to be done during a simulation. In addition, VISSIM's multi-thread capability (since VISSIM version 5.10) allows for parallel computing and hence increases simulation speed compared to single-core processors.

Who provides support for the software?  (#2)

E-mail support is available by means of a hotline form on the PTV website. Please check FAQ #72 for detailed hotline information.

Is there a demo version available?  (#1)

Yes, please check our website at
www.ptvag.com/software/transportation-planning-traffic-engineering/services/download-area/ (English) 

www.ptv.de/software/verkehrsplanung-verkehrstechnik/service/download-bereich/ (German)

for download of a demo version.

Are there any technical papers on calibration/validation available? (#12)

Yes. Please check the library on our website for technical papers.

Does the lane change model allow for merge-in-turn/zip-merge? (#11)

Yes. Merge-in-turn can be modeled e.g. at the end of a two-lane-link where the road continues as a one-lane-link. Merge-in-turn is done automatically as you use routes that stretch over this area.

Are there any default values supplied with VISSIM? (#10)

Comprehensive default values are supplied for vehicle types and classes as well as for driving and lane change behavior. The parameters of motorized traffic originate from research work done by the University of Karlsruhe.

How many different types of vehicles/drivers can be modeled?  (#9)

VISSIM uses vehicle-driver-units. There are practically no limits on the number of vehicle and driver types. By default, the vehicle types Car, HGV, Bus, Tram, Pedestrian and Bike are included. Along with all their default specifications VISSIM provides a quick project start.

What is the model time update method?  (#8)

VISSIM uses a discrete time step based model that runs at fixed time intervals. The time interval is user-definable and ranges between 0.1s and 1s.

What are the algorithms that the model uses for vehicle following and lane change? (#7)

The model uses the psycho-physical car-following model developed by Wiedemann. It uses vehicle-driver-units that incorporate several stochastical variations. Thus there are virtually no two vehicles that have exactly the same driving behavior.
For lane change a related rule-based model is used that was originally designed by Sparmann.
Continuous development of both models ensures up-to-date driving behaviour in VISSIM.

Some VISSIM dialog windows have a non suitable size or position. How can I reset to defaults? (#93)

All the window size and placement settings are stored in the registry. To restore VISSIM to the default settings, call VDIAG.EXE (contained in the same directory as VISSIM.EXE), go to "Menu and Windows" tab and press "Reset windows position".

When I try to run a simulation using the toolbar button, the following error message appears: "Runtime error: Error while reading from animation file". How can I solve this problem?  (#84)

Choose "Simulation - Continuous" from the main menu, and the simulation should run ok. 
The problem originated from the fact that the "run control" toolbar is used for simulation as well as for animation and test - whatever was used last (the current mode is indicated to the left of the buttons). 
To avoid this problem in the future, use the "Simulation" toolbar instead of the "Run Control" toolbar.

I try to run an example and there is a list of files with extensions .KFG and .SZP not found. What can I do? (#19)

At first, these files are not essential for the simulation to run. In order to correct the error, you need to open Signal Control - Edit Controllers.... For each signal control where a SZP file is missing, go to the tab "SigTimTblConfig", delete the entry next to "Configuration file" and confirm with OK. Similarly, for each missing KFG file, delete the configuration file entry on the tab "LDP Config".

Do I have to take into account any warm-up period prior to the actual simulation? (#18)

A simulation always starts with an empty network. Thus warm-up periods need to be included in order to get realistic results. This is done by enhancing the simulation period by the warm-up period and set the start of the simulation (time of day) earlier by the same amount of time. Make sure that all evaluations start after the warm-up period (by changing their start time). 
Furthermore you may use the snapshot functionality which allows to start a simulation not only from the beginning but from a simulation state saved earlier. For details, please check the VISSIM manual.

Is there a way to create an animation and show it without the hardware lock? (#16)

Yes. Every VISSIM installation CD includes a distributable VISSIM Viewer version that can be used without a hardware lock. For details, please check the VISSIM manual, chapter 2.3.
To update the Viewer to a new service pack, please check FAQ #94.

I have a situation where HGVs disappear from the network after 60 seconds of waiting time for lane change to turn left. Other vehicles would let them in, but they don't change lanes. Why? (#46)

Check if the lane where the HGV wants to change to, is closed to HGVs (button "Lane Closure..." in the link/connector window) or if the lane change to this lane is banned for HGV (button "No lane change..." in the link/connector window).

Are traffic signals fixed cycles or vehicle-actuated? (#45)

Fixed time signal control is included in the standard license. Models of several standard controllers for traffic actuated control are available as separate, independent products. Also available is VisVAP, a graphical flow chart tool to develop any type of vehicle actuated signal control.

How do I model right turn on red? (#44)

Please see the manual, section 6.6.3.

Can VISSIM model yellow boxes and keep-clear-areas? Is it possible to add the yellow box to the drawing? (#41)

Yellow boxes can be modeled using conflict areas or priority rules. See example 2 in chapter 6.6.1.4 in the manual for details on priority rules. 
Visualization of the yellow box can be done if you include it in a background graphics file. You can also load multiple background files simultaneously.

Is it possible to model overtaking into oncoming traffic lanes, e.g. for a rural single-lane carriageway? (#40)

Not directly. As VISSIM uses directional links, it is only possible at fixed locations and using priority rules, e.g. for a bus stopping at a bus stop. An example is included with the standard VISSIM installation at "..\Example\Training\SpecialModeling\OvertakeBus_OncomingTraffic".

How are banned movements specified? (#39)

When using static routes, a movement is banned if there is no route assigned to that movement (if routes do exist for at least one other movement). Routes are dependent on vehicle classes thus allowing banned turns for a certain class only.
When using Dynamic Assignment, connectors may be closed to certain vehicle classes.

How does Vissim handle grade-separated junctions? (#37)

Even if you draw links crossing each other, the program will not recognize this as an intersection unless you model connectors or any type of junction control (signal control, conflict areas and/or priority rules).

For 3D mode you may enter a height value to any link/connector to show the different levels.

Can platooning effects be modelled? (#34)

Platooning effects can be generated by

• modelling the adjacent junctions (platoons formed by signals)
• lengthening incoming links (platoons formed by car-following and different desired speeds).

How are bus lines and stops modeled? Are bus detection, signals and priority measures modelled?  (#33)

Public transport is modelled as trams and/or buses in high detail with fixed routes. Stops and timetables are modelled as well. Waiting times at stops depend on the timetable and on a user defined random distribution for the passenger interchange times. Optionally the dwell time calculation method can be chosen which uses real passenger flows to determine waiting times. Priority on signal control junctions can be modelled completely with detection and control logic using a vehicle actuated signal controller.

What other features can be modelled - e.g. blocking back, shock waves, local knowledge by some drivers (using rat runs), lane drop and gain, VMS etc.?  (#32)

Since the model is microscopic, shock waves and blocking back is modelled inherently.
Local knowledge can be modelled in Dynamic Assignment by defining different vehicle classes and allowing rat runs only for these classes.
Lane drops and gains can be modeled easily using the link parameters.
VMS and other types of traffic control can be modeled using the VAP or COM interfaces.

See also the "..\Examples" directory on your standard VISSIM installation for examples on these topics.

Is it possible to model toll booths?  (#31)

Yes, by using stop signs with an optional time distribution.

How is the route choice determined and updated during each run?  (#29)

Route choice can be determined by the user (static routing) or computed by iterated micro-simulation using the optional Dynamic Assignment module. Routing information can also be imported from the macroscopic assignment tool VISUM.

Is there any specific provision or limitation for motorways? (#26)

VISSIM has separate models for urban traffic and for motorways. Motorway junctions can be modelled using the standard network elements. Merging areas have been tested and proved against HCM standards.

What junction types are explicitly modelled (traffic signals, roundabouts, priority junctions, merges) and how?  (#25)

There are no explicit junction types thus allowing virtually any junction geometry to be modeled (including any type of roundabout).
The basic element of VISSIM networks is a link (stretch of road) with one or more lanes. Links can be modeled exactly according to the geometry of the real junction. Based on the link structure, other network elements such as signal heads, conflict areas, priority rules and merges may be defined.

Is it possible to model designated lanes, e.g. lanes that are limited by vehicle type/class, such as bus, HOV or other managed lanes? (#24)

Yes, there are various options depending on the application:

1. "Lane closure" in the link/connector attribute window
2. Vehicle class specific routing
3. Dynamic Assignment only: Connector closure

Is it possible to model pedestrian crossings? (#23)

Yes, any type of pedestrian crossing can be modelled, including zebra crossings, permitted flows (where turning vehicles need to yield to pedestrians) and signalized crossings.

See the "..\Examples\Training\SignalControl" directory on your standard VISSIM installation for examples on these topics.

What are typical times to create a network? (#22)

For a network with three simple, 4-leg junctions the geometric model will be finished within a few hours. Coding an existing signal control depends heavily on the control logic: A few minutes for a fixed time control, several hours for modeling a complex vehicle-actuated control with public transport priority.

What is the maximum size of a network that VISSIM can handle? (#21)

The largest VISSIM license has no built-in limit. Therefore the network size is limited only by computer resources. Apart from the hardware, the major factors that determine the simulation speed are number of vehicles simultaneously in the network, number of signal controls and number of possible paths (Dynamic Assignment).

Some conflict areas appear to operate with different priority than that as coded. Yielding vehicles appear to take priority. How can I avoid this?  (#102)

Before running a simulation I get a warning message that the abstract graph in the path file is not identical with the current one. What does it mean?  (#97)

If you have modified your VISSIM network and still want to continue to use an old path file, the option "Check Edges" in the Dynamic Assignment window must be enabled. Then the following errors might occur: 

• "The abstract graph (edge structure) in file *.WEG isn't identical with the current one. Error messages are written to the *.ERR file."
• "Old abstract graph in *.WEG: The edge 726 cannot be mapped to any edge in the current network graph." (*.ERR file)
• "One or more paths in file *.WEG are not used anymore. Error messages are written to the *.ERR file."
• "No edge turn in the node 10 from node 9 to node 14 could be found."

Either one of these errors means that the old structure (of the path file) cannot be safely matched with the modified VISSIM network. You either need to modify your network or you need to delete the path file and let VISSIM build a new one.

After a simulation run I get warnings in an *.ERR file that some paths could not be found. Does it mean that during the simulation not all vehicles were placed in the network?  (#96)

If the message looks like this:
"No path from parking lot 23 to parking lot 1594 can be used because of the following connector closures: 11880, for the following vehicle types: 100"
it is just a warning. It does not mean that vehicles are not placed into the network unless there is another message which states:
"No parking lot found from zone 19 with at least one path to destination zone 14.  Vehicles of type 100 from the matrix file *.FMA could not be placed in the network."

Why are some of the trips of the OD matrix not assigned? (#54)

Please check the following points:

• Is the evaluation period long enough to catch all of them? If the simulation runs for e.g. 3600 seconds and you do aggregate at the end of the same period, there will almost certainly be vehicles not yet arrived at their destination parking lot.
• Are there errors in the network topology reported to the *.ERR file? You might find out that some vehicles cannot reach their destination because there aren't any possible routes between their origin and their destination.
• Make sure that after a modification to the network topology you delete the *.BEW and *.WEG files before running the simulation again.

I use two connectors (one for each lane) when coming from a double-lane link to a single-lane link. How can I avoid unneccesary lane change due to the fact that there are two possible routes? (#51)

This way of modeling is incorrect. You only need to have one connector linking the double-lane link with the single-lane link. Because of the route functionality of VISSIM, vehicles automatically will change lanes to the one which is connected to the single-lane link - and thus there is only one possible route.

This kind of modeling is recommended both for static routes and Dynamic Assignment.

Is the cost of a route dependent only on travel time? (#49)

A generalized cost function is used instead of merely travel time. The link cost is the weighted sum of travel time, distance and link specific costs. The user has control over the weights that are used for each particular vehicle type.

Are matrix development tools available? (#48)

Matrix development tools are not part of VISSIM. However, it is possible to link up with VISUM which provides sophisticated handling of matrices and traffic demand.

Can I use Google® Sketchup® files with VISSIM? (#100)

Yes, V3DM version 1.40 includes an import for Google® Sketchup® files. As other 3D objects it can then easily be exported for use with VISSIM.
VISSIM from Version 5.20 can import Sketchup® files directly (without conversion in V3DM) as static 3D objects.

(Sketchup® is a 3D modelling tool provided by Google®. Google® also provides a large internet library of Sketchup® models incl. buildings and landmarks.)

Where can I get different video codecs for recording AVI files? (#91)

The video codecs are part of the operating system and thus VISSIM has no influence in what codecs are available or not. There is a wide range of codecs available through the internet, e.g. from
- Microsoft® 
- K-Lite
Please note that using these codecs is entirely at your own risk and outside the scope for VISSIM support.

What is the purpose of V3DM? How can I include my own 3D models in the scene? (#61)

V3DM stands for "VISSIM 3D Modeler" and is an additional VISSIM module to

• convert 3D objects from DWF, 3DS and SKP (Google® Sketchup®) format to the VISSIM V3D format
• create simple 3D objects (such as houses, simple vehicles etc.) including textures

If you would like to create more complex 3D objects you need professional 3D modeling tools such as 3DS-Max.
In VISSIM, static 3D objects (V3D format) can be inserted in 3D mode by right click.
Another option is to export VISSIM data entirely to 3DS-Max in order to create a high-end presentation of the simulation inside 3DS-Max.

Is there a way to apply background images or objects in 3D mode? (#59)

Yes, any background graphics that is loaded in 2D is also visible in 3D. Static 3D objects in V3D format (VISSIM 3D) may be placed anywhere in the network.

Several vehicle and static 3D models are included with the standard VISSIM installation. Customized models can be created/converted using V3DM (VISSIM 3D Modeler - additional module, see also FAQ #61).

Can VISSIM illustrate passengers alighting/boarding trains or buses? (#57)

Yes, this is possible with the optional pedestrian module (from VISSIM version 5.20).

As an alternative (without the pedestrian module), VISSIM can keep track of passenger flows for each transit line and stop (without visualizing them) in order to compute the dwell times of the train/bus at a stop for realistic public transport operation.

Can VISSIM use vector formats as background graphics? (#55)

Yes, among several bitmap formats (e.g. jpg, tif, bmp) also vector formats (e.g. wmf, dxf/dwg, shp, Mr. Sid) can be used for background graphics.

Is there a quick way to find the delay(s) at any given intersection without inputting travel time measurements for each movement?  (#68)

Yes, using the node evaluation (see manual chapter 11.12). 

For node evaluation (*.KNA), why do some movements have 0 volume although we could see traffic flows there by looking at the visualization?  (#95)

The node evaluation uses automatically created travel time measurements to evaluate the number and delay of vehicles for all movements. The start of the travel time section by default is max. 100m upstream of the node boundary where the link enters the node (see "Start of delay segment" in "Evaluations - Files... - Node [Filter]"). In the following cases this distance "d" is shortened:

• the link is shorter than d
• the next upstream node is less than d meters away. Then the start of the travel time section is placed directly at the next upstream node boundary. If a parking lot is placed between this node and the one to be evaluated, then the travel time section does not count all the vehicles that emerge from that parking lot.

There are different options to solve the problem:

1. Increase the length of all short entry links and place the parking lots at least d meters upstream of the node boundary.
2. Decrease d so that it accomodates for all the short entry/exit links.
3. Place the parking lots inside the node. This is in contrast to the restrictions mentioned in the manual, but it works if these two conditions are fulfilled:
   - the parking lot must be placed entirely inside the node
   - links must not end within the node polygon (otherwise an error message is generated).

Can I get the LOS (level of service) out of VISSIM? (#66)

Yes, using the VISSIM Analyzer.
Another way to measure the LOS is to measure delay times within specific segments. Matching delay and level of service is done differently in every country.

When using COM from Microsoft® Excel® to start a VISSIM simulation, I get the following message at the end: "Microsoft Excel is waiting for another application to complete an OLE action.". How can I avoid this message? (#71)

This warning message originates from Excel® and may come up, if the command "RunContinuous" is used. Choose one of the following solutions to avoid this message:

1. Use "RunSingleStep" instead of "RunContinuous" in the following way: 
   for i = 0 to simulation.Period * simulation.Resolution simulation.RunSingleStep DoEvents
   next i
2. Switch off all Excel® warnings using the VBA command:
   Application.DisplayAlerts = False
3. Use a different programming environment.

Can VISSIM model SCOOT® or SCATS®?  (#70)

You need to have a SCATS®/SCOOT® system running on your computer (this is independent of VISSIM and is not distributed by PTV).
For SCATS®, several files incl. WinTraff and ScatSim are needed from the "Roads and Traffic Authority" NSW, Australia.

My simulation runs very slow although there are less than 200 vehicles in the network. Sometimes it also looks as if the simulation speed varies a lot during one simulation. What could be the reason? (#101)

Check the following: 

• Delete all speed distributions that are not used in the simulation (especially those with higher speeds)
• At roundabouts, reduce the amount of "small" connectors (that are used for routing purposes)
• Check priority rule parameters. Avoid long gap times or headways in combination with multiple look-back paths.
• At parking lots where each space is modeled on an individual link (e.g. diagonal or perpendicular parking): On each link leading into the parking space, define a signal head (for vehicle class "Pedestrian" only) which shows permanent red. This is to avoid unnecessary look back through multiple parking lots.

What is the critical hardware component to get maximum simulation speed? (#98)

Usually, CPU speed is the deciding factor. In the rare case where the RAM is not big enough to hold the entire network with all vehicles inside at the same time, hard disk swapping takes the most time. In this case more RAM (up to 3GB) is needed. 
With the multi-thread capability of VISSIM (starting from version 5.10) you can expect a speed increase if you use multi-core-/multi-processor PCs.

How can I update the VISSIM Viewer version to the current service pack in order to pass it on to our customer? (#94)

Along with each service pack also a setup of the updated VISSIM Viewer version is posted in the service pack download area. This site also contains instructions on how to use the updated Viewer version.

There doesn't appear to be any service packs for the latest VISSIM version on the download site. I only see those of the old versions. How can I get the latest service packs?  (#79)

Some download passwords are version specific. Please use the password provided with the latest version of VISSIM in order to get the latest updates (see also FAQ #77).

Where can I find the password for downloads of VISSIM service packs? (#77)

It's contained in the file "DownloadServicePacks.txt" which is located in the directory "\Documentation" on the VISSIM installation CD.

Does VISSIM take advantage of multi-core processors and a multi-processor PC? (#74)

Yes, the multi-thread capability of VISSIM takes advantage of multi-core-/multi-processor computers if a large amount of vehicles is simulated. A multi-core-/multi-processor PC is also advisable if another application should run besides a VISSIM simulation run. 

What is the procedure of contacting the hotline? (#72)

The technical hotline is an e-mail-service operated by PTV that may be contacted 

• in case of program errors of the latest VISSIM version that cannot be solved by a procedure offered in the manual or in the FAQ section.
• by trained users of our clients that have signed a software maintainance contract with PTV directly.

In case you've purchased the software through any of our agents, please contact them directly for any enquiries.
Please use the technical hotline contact form in order to provide the relevant information. That way you contribute to a fast and efficient hotline service as we get essential hotline information already through your first contact.

This information must be included in a hotline enquiry (see also manual, chapter 14):

• Name, city and country of your company
• PTV client and dongle no.
• Version number of VISSIM incl. service pack no. (e.g. 5.20-04 - see title of main VISSIM window)
• Operating system incl. service pack no (e.g. Microsoft® Windows® Vista Business, 64-Bit Edition, Service pack 1)
• Detailed description of the problem, actions that have been taken beforehand (so that we can reproduce the error)
• The behavior you would have expected
• Screenshot (jpg) of the error message (if applicable)
• All data files necessary to reproduce the error or problem.