Unlike the Prop Span Tool, the Marking Curve and Marking Polygon Tools do not allow you to use the existing lane boundary curve to set the geometry.
However, RoadRunner provides several features with these tools to make it easier to create effective scenes.
For example:
One can use the tangent feature to adjust the curve for more precise markings.
Once the curve is created, select the desired point for adjustment. A control point will appear adjacent to the selected point.
The marking can be modified by clicking and dragging this control point as needed.
This process can be repeated for each point on the marking curve.
Marking curves can be reused by selecting, copying, and pasting them.
After a copy is created, the translation tool (located at the top-left of the toolbar) can be used for repositioning the curve as required.
I hope this helps, thanks!