Checking the network

Errors in the network impact calculations and evaluations. Use the Check network command to check the Vissim network for consistency after editing it. The command Check network can identify errors in the Vissim network and allows you to fix some of the errors immediately. Check network finds inconsistencies, e.g. incorrectly entered attribute values. However, it cannot identify missing attribute values.

Check network also finds network objects with attribute values that Vissim cannot unambiguously assign to a vehicle type: A vehicle type can be assigned to more than one vehicle class. Several of these vehicle classes can be assigned to a network object, e.g. in the case of Conflict areas, for Gaps By Vehicle Class. If for different vehicle classes, different attribute values are selected, unambiguous assignment to a vehicle type that has been assigned multiple vehicle classes is no longer possible. This also applies for pedestrian types that are assigned to multiple pedestrian classes.

• When you start the simulation, Vissim automatically checks the Vissim for certain constraints that could prevent the simulation start and performs the Check network function, if it has been selected under User Preferences (Checking and selecting the network with simulation start).
• When you call the Check network command without starting simulation, Vissim checks the Vissim network for consistency, but not for any constraints.

1.  On the Simulation menu, click > Check network.

If the Messages window is open and contains entries, these are deleted. Vissim checks the network.

• If Vissim cannot identify any errors, a window is opened and a corresponding message is displayed.
• Should Vissim using the Check network function detect that the simulation cannot be started, the Messages window opens, showing the errors.
• Should Vissim using the Check network function detect that the simulation can be started, but that there are inconsistencies, the Messages window opens, showing warnings (Showing messages and warnings).

In the Messages window, Vissim groups errors by categories. These groups, for example, inlcude:

• Driving simulator
• Scripts
• Vehicle simulation
• Vehicle classes
• Pedestrian simulation
• Pedestrian classes
• PT pedestrian simulation
• Evaluations
• Presentation
• External driver model
• Dynamic assignment
• Vehicle Routes
• Mesoscopic simulation
• Scenario Management

The entries of a group can be edited or deleted together (Showing messages and warnings).

Errors listed in the groups Vehicle routes and 2D/3D model segments can be repaired interactively, after you have corrected their network objects. During an interactive repair, Vissim for instance reconnects interrupted vehicle routes, after you have corrected the corresponding links and connectors (Showing messages and warnings). Errors of other categories must be corrected manually.

When for a 3D information sign, the reference object type and/or the reference object is deleted, Check network displays a message informing you of the respective 3D information sign. You can then select a reference object type and/or reference object of your choice or delete the 3D information sign.

You can correct individual entries or an entire group (Showing messages and warnings).

2.  Use the messages displayed to correct your Vissim network.

3.  If you correct errors in the groups Vehicle routes and 2D/3D model segments, repair these objects afterwards using the Fix command (Showing messages and warnings).