Sight Distance Analysis

Use this function for sight distance analysis. The following types of sight distance analysis can be performed:

Sight distance analysis is to be performed on the road model to verify that the necessary sight distance requirements are fulfilled.

Run the function from the following location of the floating window Road Model:

MOUS_ICO Toolbar: Sight Distance Analysis

MOUS_ICO Menu: Tools > Sight Distance Analysis

The dialog box Sight Distance Analysis will pop up.


Define the section for which analysis is to be performed.


Set the sight analysis method to use:

Note: Not all methods are available for all road standards.

Minimum sight distance requirement

Set the minimum sight distance requirement based on a road standard, or using a user-defined sight distance.

Calculation Parameter


The position of the driver on the road surface is defined using these options.

In the case of multiple lanes the desired lane or centerline itself can be used for analysis.

Surface Overlay

An overlay of specified thickness can be applied to terrain and/or roadside surfaces, to simulate the impact of vegetation, snow, etc., on sight visibility.

Reset values

All changes to parameter settings are stored within the road model. Press Reset values to reset dialog box settings to default values. The default settings are stored in a separate INI-file (RoadSA.INI) on the Novapoint installation.

Calculate >>

Having defined all the parameters, press this button to start the analysis process.

The calculation reports first column shows a listing of cross-sections in the forward direction (increasing stationing) and an equal listing in the reverse direction (decreasing stationing). Cross-sections are listed as interval defined in Settings - Stations.


When closing the dialog box, settings are stored to the road model, before returning to the Road Models main menu.

Minimum Sight Distance (formula)

Calculation of minimum required Stop Sight distances

Calculation of required stop sight distance is based on physical rules of how far a vehicle will move before it stops.

This length is divided into three components:

The theoretical background for sight distance (Ls) calculation

Ls = 0.278 * V * tr + V²/(254.3 * (f + s))

This formula is almost exactly the same as most national design standards.

Table 1: When calculating stop sight these friction coefficients are used

The slope does not influence passing sight and meeting sight distances. No calculation with regard to the vertical alignment is required, and the user-defined sight requirement is the only parameter to be evaluated.

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