2.0

Table Of Contents
Drawing Vertical Curves for the Finished Ground Centerline
201
Drawing a Vertical Curve Based on a Stopping
Sight Distance
One method of drawing a crest vertical curve is to specify a minimum stopping
sight distance.
To draw a vertical curve based on a stopping sight distance
1 From the Profiles menu, choose FG Vertical Curves to display the Vertical
Curves dialog box.
NOTE
You can use this option only with a crest curve.
2 In the Description list, select the Stopping Sight option. You can also click the
Stopping Sight icon, and then click OK.
NOTE
If you do not see the graphic representation of the curve type you want to
create, then click the Next or Previous button at the bottom of the Vertical
Curves dialog box.
3 Select the tangents that represent the grade into and out of the PVI.
4 Enter the value for the minimum stopping distance.
5 Accept the default values for Height of eye and Height of object, or enter new
values at the prompts.
The Height of eye is the height of the drivers line of vision coming down the
road and the Height of object is the height of an object in the road such as an
animal, vehicle, or piece of debris. The default values for these heights are set in
the Profile Value Settings dialog box. For more information, see Changing the
Values Settings for the Profiles in this chapter.
The length of curve is calculated.
6 Press ENTER to accept the calculate length of curve value, or enter a new value.
If you enter a new length, the command recalculates the stopping sight distance
and draws the curve with the specified length.
The following illustration shows the factors used in calculating the vertical
curve based on stopping sight distance:
Drawing a vertical curve by stopping sight distance