Three profiles drawn in CADRail. The left and right are the two I chose to use.
Each track's spline is made up of three 1.5 or 2quot; laminations (shorter splines are reserved for lower clearance locations).
One 2quot; spline ripped at a 30 degree angle creates two ballast shoulders. The center profile was an exercise to see if two ballast shoulders could create an effective ditch on a double track main. They would, but the resulting track spacing would be too wide.