This category allows you to view and edit the splitter island envelope offsets.

Design Guidelines' Splitter Island Envelope Category 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.

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.

Default Splitter Type (Turbo Vehicle Envelopes Design Method)

Select the type of splitter that will draw by default when legs are added to the turbo roundabout.

• Entry/Exit Straight: The entry and exit sides of the splitter are drawn parallel to the leg reference geometry. This option also includes the ability to specify a default median width that allows the leg to be generated with a median.
• Entry/Exit Offset: The entry and exit sides of the splitter are drawn based on the entry and exit lane offsets.
• Entry Offset / Exit Straight: The entry side of the splitter is drawn based on the entry lane offset while the exit side is drawn parallel to the leg reference geometry.
• Entry Straight / Exit Offset: The entry side of the splitter is drawn parallel to the leg reference geometry while the exit side is drawn based on the entry lane offset.

Default Median Width (Turbo Vehicle Envelopes Design Method)

Specify the median width value. This value is only available for the Entry/Exit Straight option.

Inscribed Circle to Splitter Island Envelope Offset (Vehicle Envelopes Design Method)

Construction Line to Splitter Island Envelope Offset (Turbo Vehicle Envelopes Design Method)

Specify the inscribed circle to splitter island envelope offset value. This is the distance from the inscribed circle diameter (Turbo: outside circulating lane's outer construction line) to the closest point of the splitter island envelope.

Entry Lane to Splitter Island Envelope Offset

Specify the entry lane to splitter island envelope offset value. This is the distance from the closest tire track of the vehicle to the splitter island envelope on the entry side.

Exit Lane to Splitter Island Envelope Offset

Specify the exit lane to splitter island envelope offset value. This is the distance from the closest tire track of the vehicle to the splitter island envelope on the exit side.

Splitter Island Envelope Length

Specify the splitter island envelope length value. This is the distance from the splitter island envelope edge closest to the roundabout to the outside edge.

Legend

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.