Objects and attributes

Apart from links and nodes, you can model accidents, black spots, and sections in Visum Safety.

Accidents

Accidents are point-POIs which are allocated to a node, a link or a main node if possible (Editing accidents). As there may be a lot of information stored for each accident, only a part of this data is imported to Visum as user-defined POI attributes. The main part of the data is contained in a database file *.vsaf.

Accidents should not be created in Visum, but rather be imported together with their data. Via the shortcut menu of the object button, you can import accident data from a *.csv file.

If accidents are not positioned automatically during the import, you can position them manually and allocate them to links or nodes. Furthermore, you can filter unassigned accidents and allocate them automatically according to the desired criteria.

Note: Detailed information and statistics on the currently selected accidents will be shown in a separate window if you click the icon.

Black spots

Black spots are polygon POIs. They are used to monitor and prioritize sites with high accident counts (Editing black spots). Visum Safety provides methods to accumulate data for all accidents contained in these polygons.

Black spots are created at nodes or accidents and can be generated automatically at sites with high accident counts.

Sections

You can aggregate links into sections to analyze a sequence of links and nodes (Editing sections). You can generate sections automatically for selected links.

Attributes of nodes, main nodes and links

For each node and main node, the following attributes are automatically calculated based on the currently filtered accidents:

  • Accident count
  • Accident rate (accidents per million vehicles)
  • Accident cost

For each link, the following attributes are automatically calculated based on the currently filtered accidents:

  • Accident count
  • Accident density (accidents per kilometer)
  • Accident rate (accidents per million vehicle kilometers)

The same attributes exist also for accident costs.

You can easily visualize this data using the simplified Graphic parameters window (Editing the display settings for nodes and Editing the display settings for links). If you select an attribute, the program will automatically create equally distributed graphic parameter classes ranging from green (low values) via yellow (medium values) to dark red (values above the set threshold value).