Well, a correction to my "final word" is in order: I said "spike the first six inches along the end of the straight centerline in three places, so that one edge of the rail base is against the centerline." This is incorrect. You should place the center of your spline at the approximate location where the tangent ends and the curve begins. Then spike the spline to the straight section some distance AWAY from this location, then ditto for the curved section.
You will discover that the tighter the radius, the greater the length of the easement. The key is to find the spiral that requires the least manual force to maintain without the spline flopping around. Dick Karnes
