Hi,
That's possible with the help of the "Auto Align" option of the Extend X/Y Size to Area mode (the Auto-Align feature "replaces" this multiple object creation). This option creates an array aligned automatically with each sub-spline, which is very suitable for this kind of scenario. Two modes are available, and for both modes, the Z-axis is always perpendicular to the plane formed by the spline. a) "X --> XY": The X-axis is parallel to the RailClone XY plane (considering the local axis of the object). b) "to Spline" (a recommendable one for your scene): The X-axis is aligned with the first Spline segment (you can use the "Make first" vertex and "Reverse" spline to modify alignment).
I hope that helps.
Best regards,