OverlayWidenFromCurb

This subassembly is used to overlay one side of an existing road, and add one or more travel lanes to the edge going around a curb return.

It is similar to the OverlayWidenMatchSlope1 subassembly, except that it extends inwards from an existing or proposed curb flange point.

Attachment

The attachment point is at the outside edge of the lane widening section. Typically this subassembly is inserted inwards from the flange of an existing or proposed curb and gutter, or from the outside edge of pavement around a curb return.

Input Parameters

Note: All dimensions are in meters or feet unless otherwise noted. All slopes are in run-over-rise form (for example, 4 : 1) unless indicated as a percent slope with a “%” sign.

Parameter	Description	Type	Default
Side	Specifies which side of the attachment point this subassembly will be added.	Boolean	Left / Right
Widening Width	Width of the widening lane.	Numeric, positive	3.6 m 12.0 ft
Overlay Width	Width of the pavement overlay.	Numeric, positive	3.6 m 12.0 ft
Slope	Slope of the overlay and widening.	Numeric	- 2%
Pave1 Depth	Thickness of the Pave1 layer for the lane widening; zero to omit.	Numeric, positive	0.025 m 0.083 ft
Pave2 Depth	Thickness of the Pave2 layer for the lane widening; zero to omit.	Numeric, positive	0.025 m 0.083 ft
Base Depth	Thickness of the base layer for the lane widening.	Numeric, positive	0.100 m 0.333 ft
Subbase Depth	Thickness of the subbase layer for the lane widening.	Numeric, positive	0.300 m 1.0 ft

Target Parameters

This section lists the parameters in this subassembly that can be mapped to one or more target objects, such as a surface, alignment, or profile object in a drawing. For more information, see To Specify Corridor Targets.

Parameter	Description	Status
Existing Surface	Name of the Surface defining the existing roadway. The following object types can be used as targets for specifying this surface: surfaces.	Required
Widening Offset	May be used to override the fixed Widening Width and tie the inside edge of widening to an alignment. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines, or survey figures.	Optional
Offset Overlay	May be used to override the Overlay Width and tie the inside edge of overlay to an alignment. The following object types can be used as targets for specifying this offset: alignments, polylines, feature lines, or survey figures.	Optional
Overlay Profile	May be used to override the Slope and tie the elevation of the inside edge of overlay to a profile, resulting in a calculated slope. The following object types can be used as targets for specifying this elevation: profiles, 3D polylines, feature lines, or survey figures.	Optional

Output Parameters

Parameter	Description	Type
%Slope	The calculated slope on the existing surface from the Sample Point to the Insert Point	Numeric

Behavior

The attachment point determines the offset and elevation of the outside edge of widening. The location of the inside edge of widening and inside edge of overlay are determined using the given widths and slope. Alignments can be used to override the given numeric widths. If the Overlay Profile is given, then the slope is calculated between the profile elevation at the inside edge of the overlay and the attachment point.

The following illustration shows a situation with an overlay offset profile. (If the Overlay Profile is given, then the slope is calculated between the profile elevation at the inside edge of the overlay and the attachment point.)

The following illustration shows a situation with no overlay offset profile.

It is important to note that slope from the left to right of this subassembly is the same. Also, the same slope is applied to all subsurfaces.

Finally, if overlay profile is attached, then we have to add vertical links (a) from “overly offset” to target (EG) surface, and (b) from end of overlay and beginning of widening to target (EG) surface, and (c) add links between two points along (tracing) target (EG) surface links.

The area formed by this shape is to be coded as “Overlay” (S1) below in the coding diagram.

The overlay is the area between the top of the overlay and the existing ground, and may be a non-uniform depth.

Layout Mode Operation

In layout mode this subassembly is attached to any convenient point. The subassembly is shown at the given widths and slope. In modeling mode, the shapes adjust to the actual conditions defined by the existing surface and Runtime Logical alignments and profile.

Point, Link, and Shape Codes

The following table lists the point, link, and shape codes for this subassembly that have codes assigned to them. Point, link, or shape codes for this subassembly that do not have codes assigned are not included in this table.

Point, Link, or Shape	Codes	Description
P5	ETW	Outside edge of widening lane on finish grade
P7	ETW_Pave1	Outside edge of widening lane on Pave1
P9	ETW_Pave2	Outside edge of widening lane on Pave2
P11	ETW_Base	Outside edge of widening lane on Base
P13	ETW_Sub	Outside edge of widening lane on Subbase
L1, L5	Top, Pave	Finish grade surface
L2	Overlay	Superimposed over links on the Existing Surface. Note, there may be more than a single link between points P3 and P4.
L6	Pave1
L7	Pave2
L8	Base
L9	SubBase, Datum
L10	Datum
S1	Overlay	Area between the overlay and existing lane.
S2	Pave1
S3	Pave2
S4	Base
S5	SubBase