Override the bypass lane offsets specified in the current Design Guidelines' Bypass Lane Offset Category.

Configure Bypass Lane 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.

For a description of the elements drawn in the roundabout in this category, see Roundabout Illustration Legend.

For a description of the elements drawn in the turbo roundabout in this category, see Turbo Roundabout Illustration Legend.

Bypass Lane Type Section (Vehicle Envelopes Design Method)

• Select Free-flow to set the offset direction from the ICD (Inscribed Circle Diameter) to the closest point of the bypass lane edge (away from the center of the roundabout), outside of the ICD.
• Select Partial to set the offset direction from the ICD (Inscribed Circle Diameter) to the closest point of the bypass lane edge (towards the center of the roundabout), encroaching the ICD.
• Select User-Drawn and then click Pick Geometry to select the user-drawn polyline (complex-chain), consisting of lines and arcs, that represents the inside edge of the bypass lane. The geometry must cross the outside edge of the entry and adjacent exit lane.

Example of User-Drawn Bypass Lane Geometry

Override Bypass Lane Vehicle Section

Select this check box to override the design vehicle specified in the current Design Guidelines' Vehicles Category: Bypass Lane. Select a design vehicle specified for the current design guideline in the list or click Select Vehicle to select from the complete list of Design Vehicles.

Inscribed Circle to Bypass Lane Offset (Vehicle Envelope Roundabout Design Method)

Specify the bypass lane offset value. This is the distance from the inscribed circle diameter to the closest point of the bypass lane edge.

Construction Line to Bypass Lane Offset (Turbo Roundabout Design Method)

Specify the bypass lane offset value. This is the distance from the outside circulating lane's outer construction line to the closest point of the bypass lane edge.

User-Drawn Bypass Lane (Vehicle Envelope Roundabout Design Method)

Dedicated Entry / Exit

Select this check box if the bypass lane is to have a dedicated (additional) lane at the entry/exit portion of the bypass lane.

Entry / Exit Opening Width

Specify the width of the bypass lane at the entry/exit portion of the bypass lane.

Bypass Lane Width

Specify the width of the bypass lane.