Link Related

1. Network

Select the overlay that will receive the thematic result of the risk calculation.

For example:

2. Results Column

This entry specifies the Results Column.

• The risk calculation will result in the items in the spatial reference overlay receiving an attribute with their individual risk value.
• A default name will be suggested for this attribute (based on the type of risk calculation and the date the command is run.)

For example:

You can change this name. Simply ensure it follows SIS Desktop property naming conventions i.e. alphanumeric and underscore characters only.

TIP: The # need not be entered into the Results Column box.

This property is added to the overlay’s schema.

If the schema already includes a property of this name, you will be warned about existing values that may be overwritten:

3. Create results as

Schema column and theme on selected overlay.

Schema column and theme on selected overlay: The Geography units entry at the top of the dialog specifies the overlay on which the resultant risk map is to be based (e.g. super output areas.)

If the selected spatial reference overlay is not editable, only the New internal overlay (copy of selected overlay) option is made available.

4. Load Risk Model

Click Load Risk Model button to load a previously saved risk model.

Click Next to open the Link-related risk options.

1. Data to snap to network Overlay

Select the overlay containing the data contributing to the risk – all overlays are listed, e.g. the analysis can be performed on an invisible overlay.

Note: (Workload Modeller’s Check Filter command can be used to create an overlay of RTC data).

2. Maximum snap distance (m)

Specify the maximum snap distance in metres,

If an incident is further away from the network than this specified distance, the incident will not be included.

3. Create density report

Choose whether a density report is required. This collates ‘snaps’ by Class and optionally Subclass with occurrence per mile or km (density).

Example reports:

The following example Density Report report is based on ITN's DescriptiveTerms$ attribute:

The following example Density Report is based on ITN's DescriptiveTerms$ and NatureOfRoad$ attributes:

Click Export to save the report as a .csv file.

Click Next.

The risk values will be calculated. This process may take some time; check the progress bar periodically.

Once the values have been calculated, you can set theme styles.

Use the drop-down menu to set the theme style.

There are two sets of Themes:

1. RAG: Red Amber Green risk colours
2. Heat – based on green to red hotspot colours.

TIP: Themes are defined in the Risk Modeller's configuration file: riskModellerConfig.xml.

Use the second drop-down to define how the bands are calculated for the current set of results (i.e. by Equal Range, Percentiles or Equal Count.)

A note on Percentiles:

Percentile band values can be changed by editing the values in the >=

The theme Band ranges can be manually adjusted by entering new values in the >=Min column. These are then used as the defaults for future uses of the theme.

The decision to use any of these options depends on the actual values.

Check the Ignore zero values tickbox if required.

Click Options to display the Theme Settings dialog:

Option	Description
Theme pen for geography units	If required change the pen style by selecting a style from the Style drop-down box.
When ignoring zero values	Check the Set zero values blank in theme tickbox to prevent all zero values which could result in large areas of colour being shown in the output grid.
Theme Labels	Check the Label ranges with numeric limits tickbox to label the ranges with numeric values.

Click OK.

Click Save Risk Model if you want to save the risk model settings. The model settings are saved as a .JSON file.