LaneFromTaperedMedian2

This subassembly inserts one or more travel lanes outward from an alignment that defines the edge of a median.

The alignment defining the edge of the median may at times be either not present (Case 1), outside the roadway centerline (Case 2), or inside the centerline (Case 3).

To use this subassembly, you should have separate alignments defining the left and right edges of the median. It may be necessary to define separate corridor model regions for each individual median. This subassembly differs from LaneFromTaperedMedian1 in that it provides for a grade break with different slopes in the travel lanes.

Attachment

The attachment point is at the location where the inside edge-of-traveled-way would be if there was no median. This is typically at the assembly baseline.

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	Indicates the outward direction of the lane	Left / Right	Right
Inside Lane Width	Width of the inside lane for the condition where there is no median; that is, from the attachment point to the grade break point.	Numeric	3.6 m 12.0 ft
Inside Lane - Use Superelevation Slope	Specifies to use the superelevation slope for the inside lane. Choices are No, Outside Lane Slope, and Inside Lane Slope.	String	Inside Lane Slope
Default Inside Slope	Specifies default slope for the inside lane. This value is used if superelevation slope is not used, or is not specified for the baseline alignment.	Numeric, positive	2.0%
Outside Lane - Use Superelevation Slope	Specifies to use the superelevation slope for the outside lane. Choices are No, Outside Lane Slope, and Inside Lane Slope.	String	Outside Lane Slope
Default Outside Slope	Specifies default slope for the outside lane, if superelevation slope is not specified.	Numeric, positive	- 2.0%
Outside Lane Width	Width from the grade break point to the outside edge-of-traveled-way.	Numeric	3.6 m 12.0 ft
Inside Adjustment	Used if the Median Edge alignment is at a fixed offset from the actual edge-of-traveled-way (for example, at the back of curb). Adjusts the calculated Inside Lane Width to account for the offset (see diagram).	Numeric, positive	0.0
Outside Adjustment	Used if the Outside Lane Width alignment is at a fixed offset from the actual edge-of-traveled-way (for example, at the back of curb). Adjusts the calculated Outside Lane Width to account for the offset (see diagram).	Numeric, positive	0.0
Pave1 Depth	Depth between finish grade and Pave1 (zero to omit)	Numeric, non-negative	0.025 m 0.083 ft
Pave2 Depth	Depth between Pave1 and Pave2 (zero to omit)	Numeric, non-negative	0.025 m 0.083 ft
Base Depth	Depth between Pave1 and Base (zero to omit)	Numeric, non-negative	0.100 m 0.333 ft
Subbase Depth	Depth of the Subbase layer at the attachment point (zero to omit)	Numeric, non-negative	0.300 m 1.0 ft

Note that if the Inside %Slope value is always the same as Outside %Slope, or if Inside Lane Width is zero, then the simpler LaneFromTaperedMedian1 subassembly can be used instead.

Target Parameters

This section lists the parameters in this subassembly that can be mapped to one or more target objects. For more information, see To Specify Corridor Targets.

Parameter	Description	Status
Median Edge	May be used to shift the starting offset of the lane to follow an edge-of-median alignment. The following object types can be used as targets for specifying this: alignments, polylines, feature lines, or survey figures.	Optional
Inside Lane Width	May be used to override the fixed Inside Lane Width and tie the grade break to an offset alignment. The following object types can be used as targets for specifying the width: alignments, polylines, feature lines, or survey figures.	Optional
Outside Lane Width	May be used to override the fixed Outside Lane Width and tie the edge-of-lane to an offset alignment. The following object types can be used as targets for specifying the width: alignments, polylines, feature lines, or survey figures.	Optional
Outside Elevation	May be used to override the normal lane slope and tie the outer edge of the travel lane to the elevation of a profile. The following object types can be used as targets for specifying the elevation: profiles, 3D polylines, feature lines, or survey figures.	Optional

Output Parameters

Parameter	Description	Type
Superelevation Axis of Rotation	Indicates whether the subassembly supports the axis of rotation calculation. To view a description of the parameter, in the Properties window, hover the cursor over the parameter. For more information, see Profile Grade Line Adjustments During Superelevation.	Static (Description)
Inside Lane Width	Width of the inside lane	Numeric
Inside Lane %Slope	% slope of the inside lane	Numeric
Outside Lane Width	Width of the outside lane	Numeric
Outside Lane %Slope	% slope of the outside lane	Numeric

Behavior

Grade Break: The width from the attachment point outwards to the grade break between the inside and outside lanes can be defined by a fixed numeric width, or an alignment can be used to override the width. The elevation at the grade break is determined by applying the specified slope for the inside lane across the width of the lane.

Outside Edge-of-Traveled-Way: The width to the outside edge-of-traveled-way can be defined by a fixed numeric width, or an alignment can be used to override the width. The elevation is determined by applying the specified slope for the width of the lane, unless an Outside Elevation profile is given. In that case, the outside edge elevation is tied to the profile, and the slope is adjusted.

Inside Edge-of-Traveled-Way: The location of the inside edge-of-traveled-way is calculated based on the three cases shown in the previous diagram. If a Median Edge alignment is given, and that alignment is outside of the lane’s attachment point, the inside edge is shifted outward from the attachment point at the lane slope (Case 2). If the Median Edge alignment is inside of the lane’s attachment point, the inside edge is shifted inward from the attachment point at the inside lane slope (Case 3). If no Median Edge alignment is given, or the given one is not found at a station, the inside edge is held at the attachment point (Case 1).

Inside and Outside Adjustments: The Inside Adjustment and Outside Adjustment parameters are provided in case the alignments used for the inside or outside edges are at a fixed offset from the actual edge-of-traveled-way. For example, the alignment being used for the Median Edge may be at the back-of-curb instead of at the pavement edge. In this case, the Inside Adjustment parameter should be set to the width of the curb.

Layout Mode Operation

In layout mode, this subassembly displays the links comprising the lanes for the given widths and slopes. If a superelevation slope is given (LI or LO), the links are displayed at a slope of -2%.

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	Code	Description
P1, P3	ETW	Edges of lane on finish grade
P4, P6	ETW_Pave1	Edges of lane on Pave1 layer
P7, P9	ETW_Pave2	Edges of lane on Pave2 layer
P10, P12	ETW_Base	Edges of lane on Base layer
P13, P15	ETW _Sub	Edges of lane on Subbase layer
P2	Crown	Crown (grade break) on finish grade
P5	Crown_Pave1	Crown (grade break) on Pave1
P8	Crown_Pave2	Crown (grade break) on Pave2
P11	Crown_Base	Crown (grade break) on Base
P14	Crown_Subbase	Crown (grade break) on Subbase
L1, L2	Top, Pave	Finish grade surface
L3, L4	Pave1	Pave1 surface
L5, L6	Pave2	Pave2 surface
L7, L8	Base	Base surface
L9, L10	SubBase, Datum	Subbase surface
S1	Pave1	Area between finish grade and Pave1
S2	Pave2	Area between Pave1 and Pave2
S3	Base	Area between Pave2 and Base
S4	SubBase	Area between Base and Subbase