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.
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.
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.
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.
This section lists the parameters in this subassembly that can be mapped to one or more target objects. For more information, see in the AutoCAD Civil 3D User’s Guide Help.
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 |
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.
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%.
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.
