Draw Slip Lane Dialog Box

Use this dialog box to specify details for adding a slip lane (or bypass lane) to a roundabout.

Note: This functionality has been replaced by the new roundabout feature and is included here for compatibility reasons. For current roundabouts, see About Roundabouts.

In some roundabouts, a slip lane can be added between an approach road and a departure road to reduce the traffic moving through the circular area of the roundabout.

Slip Lane Parameters

These parameters specify the geometry of an optional slip lane that can be added to a roundabout.

To see a conceptual illustration of the parameter location, place your cursor in the entry field for the parameter. The conceptual illustration is displayed in the dialog box.

Segmentation Line Length

To achieve the correct geometry in approaches with base alignments that are not straight, the deceleration lane and taper are segmented. The default value of the segment length is 1 unit. Note that lower values will improve accuracy, however reduce the speed of operation.

Lane Width

Specifies the width of the slip lane.

Length of Deceleration Lane

Specifies the length of first part of the slip lane where the vehicle will decelerate and bear onto the right or left turning lane.

Radius

Specifies the radius of an arc in the middle of the slip lane.

Length of Acceleration Lane

Specifies the length of the road where a vehicle will accelerate to merge into a main road.

Taper Length

Specifies the length of the road where a vehicle will merge into a main road.

Draw Pavement Markings

Specifies pavement marking for slip lane components. You can specify a linetype, width, and an offset. If you do not want pavement markings, clear the check mark from the Draw check box.

Outer Edge

Specifies the pavement markings for the outer edge of the slip lane.

Decelerating Transition Line

Specifies the pavement markings for the decelerating transition line of the slip lane.

Accelerating Transition Line

Specifies the pavement markings for the accelerating transition line of the slip lane.

Draw

Specifies whether or not to add (draw) the pavement markings.

Linetype

Specifies the linetype of the pavement markings.

Width

Specifies the width of the pavement markings.

Offset

Specifies an offset for the pavement markings.

Alignment Style

Specifies the alignment style from the list of styles available in the drawing.

Alignment Layer

Specifies the alignment layer from the list of layers available in the drawing.

Alignment Label Set

Specifies the alignment label set from the list of label sets available in the drawing.

Alignment Name Prefix

Displays the name of the alignment used to specify the central approach road. This name is used as a prefix for the alignments that are generated by the roundabout creation. For the right edge alignment, the suffix “_EDGE_RIGHT” will be added to the alignment name. For the left edge alignment, the suffix “_EDGE_LEFT” will be added to this name.