Option

Description

Eye height

Enter the eye height of the driver.

Object height

Enter the height of the object the driver must be able to see over the minimum sight distance.

Eye offset from CL / MBP

Enter the offset of the driver from the centre line if the road is a single carriageway, or the offset from the median break point for a dual carriageway.

Minimum Sight Distance

Enter the minimum sight distance in m. This is the distance over which the driver must be able to see the object.

Object offset from CL / MBP

Enter the offset of the object from the centre line if the road is a single carriageway, or the offset from the median break point for a dual carriageway.

Road Settings

Start chainage

Specify the chainage where you want the sight distance calculations to start.

End chainage

Specify the chainage where you want the sight distance calculations to end.

Base Layer

Specify the layer where the ground cross-sections are stored.

Batter Layer

Specify the layer where the final design cross-sections are stored.

Road Reserve Settings

Click to display the Road Reserve Settings. The Sight Distance check will fail horizontally if the line of sight crosses the road reserve.

Dual Carriageway Settings

Check on

This option is only available for dual carriageway roads. Select the carriageway on which to do sight distance checking.

Chain direction

This option is only available for dual carriageway roads. Select the direction (Ascending or Descending) in which the sight distance checking should be done.

For Single carriageway roads, the sight distance checking will be done in both directions automatically.

No Sight envelope settings

Ascending chain direction

Enter the pen colour in which the program will indicate the areas where the driver can not see the object over the specified minimum sight distance in the ascending chainage direction.

 Descending chain direction

Enter the pen colour in which the program will indicate the areas where the driver can not see the object over the specified minimum sight distance in the descending chainage direction.

Horizontal Failure LT

Select the line type to be used to mark areas where the sight distance check fails due to the horizontal alignment not allowing sufficient sight distance.

Profile Failure LT

Select the line type to be used to mark areas where a full 3D sight distance check fails. This will check if the sight line intersects with any cut bank, vertical curve or even berms and kerbs.

Envelope to CAD

Select this checkbox if you want the envelopes to be sent to a CAD layer as line segments. Type in the layer name.

Show in Vertical Alignment

Select this checkbox to display the no-sight envelope in the Vertical Alignment view. The envelope will be drawn on the vertical, as well as horizontal, alignments. If you are already in the Vertical or Horizontal alignment functions, this option will be disabled.

Option

Description

Eye height

Enter the eye height of the driver.

Object height

Enter the height of the object the driver must be able to see over the minimum sight distance.

Eye offset from CL / MBP

Enter the offset of the driver from the centre line if the road is a single carriageway, or the offset from the median break point for a dual carriageway.

Object offset from CL / MBP

Enter the offset of the object from the centre line if the road is a single carriageway, or the offset from the median break point for a dual carriageway.

Layer Settings

Base Layer

Specify the layer where the ground cross-sections are stored.

Batter Layer

Specify the layer where the final design cross-sections are stored.

Road Reserve Settings

Click to display the Road Reserve Settings. The Sight Distance check will fail horizontally if the line of sight crosses the road reserve.

Dual Carriageway Settings

Check on

This option is only available for dual carriageway roads. Select the carriageway on which to do sight distance checking.

Chain direction

This option is only available for dual carriageway roads. Select the direction (Ascending or Descending) in which the sight distance checking should be done.

For Single carriageway roads, the sight distance checking will be done in both directions automatically.

Measurement Interval

Specify the chainage interval along the road at which sight distance measurements will be taken. This value cannot be smaller than your coordination interval.