David Stokes says:

Superelevation in model railways is a visual attraction that serves little or no mechanical function. Do it – it looks great when done well, and your trains will look great. However, have you considered transition curves on your layout. Now these DO improve the way trains move. A train travelling on a tangent (straight track) will try to continue to travel in a straight line when approaching into a curve, and needs to be persuaded to go round that curve. Without a transition curve the change in direction is a sudden and visually jarring experience. The train doesn’t “flow”. By installing a short, slightly larger radius section of track before the main curve, the train is coaxed into the curve in a well mannered proper fashion . Look up “Transition curves” on the net for how to do it. You won’t be disappointed.