Override the splitter island offsets, exit/entry radii, length and corner radii as specified in the current Design Guidelines' Splitter Island Category.

Configure Splitter Island 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.

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

Vehicle Envelopes Design Method

Single Splitter Island Terms

Circulatory Entry / Exit Offset

This is the distance from the edge of the circulatory roadway or ICD to the splitter island on the entry / exit side of the leg.

Entry / Exit Circulatory Radius

This is the radius of the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Entry / Exit Circulatory Offset

This is the distance from the splitter island envelope to the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Entry / Exit Tip Offset

This is the distance from the splitter island envelope to the splitter island closest to the tip of the island.

Tip Radius

This is the radius of the tip of the splitter island.

Inside Splitter Island Terms

Inside Splitter Circulatory Entry / Exit Offset

This is the distance from the edge of the circulatory roadway or ICD to the splitter island on the entry / exit side of the leg.

Inside Splitter Entry / Exit Circulatory Radius

This is the radius of the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Inside Splitter Entry / Exit Circulatory Offset

This is the distance from the splitter island envelope to the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Inside Splitter Entry / Exit Tip Offset

This is the distance from the splitter island envelope to the splitter island closest to the refuge/crosswalk on the entry / exit side of the leg.

Inside Splitter Entry / Exit Tip Radius

This is the radius of the splitter island closest to the refuge/crosswalk on the entry / exit side of the leg.

Inside Splitter Entry / Exit Refuge/Crosswalk Offset

This is the distance from the refuge/crosswalk to the splitter island on the entry / exit side of the leg.

Outside Splitter Island Terms

Outside Splitter Entry / Exit Refuge/Crosswalk Offset

This is the distance from the refuge/crosswalk to the splitter island on the entry / exit side of the leg.

Outside Splitter Entry / Exit Circulatory Radius

This is the radius of the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Outside Splitter Entry / Exit Circulatory Offset

This is the distance from the splitter island envelope to the splitter island closest to the circulatory roadway or ICD on the entry / exit side of the leg.

Outside Splitter Entry / Exit Tip Offset

This is the distance from the splitter island envelope to the splitter island closest to the tip of the splitter island on the entry / exit side of the leg.

Outside Splitter Tip Radius

This is the radius of the tip of the splitter island.

Regional Design Method

Splitter Island ICD (Inscribed Circle Diameter) Offset

Specify the splitter island ICD offset value. This is the distance from the edge of the ICD to the splitter island.

Splitter Island Envelope Entry Radius (British Regional Design Method)

Specify the splitter island envelope entry radius value.

Splitter Island Entry Offset

Specify the splitter island entry offset value. This is the distance from the entry width (British: edge created by the entry radius) to the splitter island on the entry side.

Splitter Island Envelope Exit Radius (British Regional Design Method)

Specify the splitter island envelope exit radius value.

Splitter Island Exit Offset

Specify the splitter island exit offset value. This is the distance from the exit width (British: edge created by the exit radius) to the splitter island on the exit side.

Splitter Island Length

Specify the length of the splitter island.

Corner Radius

Specify the corner radius value in the box (French: or click Calculate Corner Radius and then specify a factor to calculate the value or vice versa).