Vehicle Envelopes Design Method - Australian

Generates and edits roundabout designs by applying design guidelines (see Design Guidelines) to user-drawn reference geometry by ‘driving’ the design vehicles through the design to determine the locations of the road edges.

Vehicle Envelopes Design Methods Note: TORUS creates road edges based on vehicle envelope geometry which represents the minimum space for the design vehicle to maneuver. To generate an approximation of roundabout refined edges from the vehicle tire track envelope, use the Refine Edges tool.

Pavement Markings Note: When you use the Edit Roundabout tool to select a roundabout, all pavement markings edited using GuideSIGN Markings features will be reset to their default state.

Note:

• For the purposes of describing the software, it is assumed that Right-Hand Traffic is selected under Traffic Direction in Design Guidelines' General Category. If Left-Hand Traffic is selected, the descriptions with references to a right/left turn path should be interpreted in the opposite direction.

• This tool requires the presence of user-drawn lines and/or arcs to become reference geometry for the roundabout design. Using the line and/or arc tools in AutoCAD or MicroStation, draw the reference geometry that represents the roundabout’s approach leg centerlines.

  • The reference line length defines the maximum limits of the corresponding splitter island envelope.
  • The reference line defines the separation of the traffic flow directions and normally aligns parallel with the straight section of the median closest to the center of the roundabout.

• It is recommended that you create a new design guideline appropriate for the current design (see Design Guidelines' New Design Guideline).

For an example of how the Generate Roundabout tool works, please play the Generate Roundabout tutorial (for information on how to play a tutorial, see Tutorials -> Play).

Generate Roundabout / Edit Roundabout Dialog Box

In the dialog box, move the mouse pointer over the controls to view the associated tooltip and then reference the controls described below.

Design Guideline Section

Design Guideline

Select the desired Australian Vehicle Envelopes design guideline from the list.

View

Click this button to view the selected design guideline.

Note:

• As you select a design guideline, its parameters are automatically applied to the current roundabout. To return to the previous design guideline parameters, select the original guideline in the Design Guideline list.
• After you place the central island and add at least one approach leg, you will be able to select only those design guidelines that use the same design method as the current design guideline.

Central Island Geometry Section

Button	Option	Click to...
Configure	Configure Central Island	Change the central island's shape and dimensions.

Visibility and Configuration Section

Button	Option	Click to...
Visibilities and Configurations	Visibilities and Configurations	Set which aspects of the roundabout are drawn in the roundabout and allows certain aspects to be configured.

Toolbox Section

Button	Option	Click to...
	Add Legs	Add one or more approach legs to the roundabout.
	Edit Legs	Edit approach legs' parameters.
	Replace Leg Reference Geometry	Replace the reference element of an approach leg by picking a different reference element in the drawing. Note: An alternative to using this tool is modifying the reference geometry of an approach leg directly in the drawing by using object grips. If you drag a grip of a line, an arc, or a polyline reference element, the roundabout design will update accordingly.
	Delete Leg	Delete an approach leg from the roundabout.
	Edit Markings	Turn markings on/off, and/or change the arrow and/or yield line type used in pavement markings.
	Set Secondary Leg Reference	Pick a second reference element for the exit lanes of an approach leg.
	Rotate Leg	Rotate an approach leg around the center of the central island by moving the mouse pointer around the central island as desired.
	Save Roundabout Template	Save the current roundabout design as a template so that it can be used with the Roundabout Wizard tool. Note: This button is only available when the roundabout has at least three legs.
	Save Roundabout Iteration	Save the current roundabout design as an iteration so it can be recalled later.
	Generate Roundabout Report	Generate a roundabout summary report.