Input Spline Shape @ Runtime

[Elenesski]

How do I assign an InputSplineShape at runtime?  I want to have a road that contains 2 lines with a yellow line running down the middle.  Now I want to expand it to a divided highway.  To do this, I need to change the shape and the texture.  How do I assign/reassign the shape, because this doesn't work as I expected it to.  Do I need to use a method instead?  if so what?

                        InputSplineShape SHAPE = GENERATOR.AddModule<InputSplineShape>();
                        SHAPE.FreeForm = true;
                        SHAPE.Shape = Road[0];

Where Road[0] is a CurvySpline and the two lane road shape and Road[1] is the divided highway shape.

                        var RECTANGLE = SHAPE.SetManagedShape<CSRectangle>();
                        RECTANGLE.Width = 40;
                        RECTANGLE.Height = 25;

This code gives me a rectangle and the shape is as I expected.  So, how do I assign/reassign the shape at runtime?

Thanks,
El