\tangent another solution is camber or cant, where the outer rail is higher, banking into the curve, as an aeroplane turns.<p>A problem is the beginning of a curve. If the straight simply becomes an arc of a circle, the lateral centrifugal force (see xkcd) goes instantaneously from 0 to maximum. One might think an Euler spiral, whose rate of turn increases linearly, would fix this; but now, although the lateral force increases linearly, the onset of change in force is instantaneous, and is felt as a jolt by passengers. Apparently it is possible to create turns giving a smooth ride, but requires sophisticated dynamic models that are presently beyond me.<p>I started making a game with very smoothly transitioning banked turns, but it&#x27;s a lot more complex than I thought! (Other games use tilting-like mechanisms, such as suspension, and the natural averaging over the four contact points of a car, but that&#x27;s not applicable to what I want to do).  If anyone has some pointers, I&#x27;d love to hear them!<p>P.S. Re trains: Of course, another problem is that banked turns are &quot;static&quot;, the same for all trains regardless of velocity; whereas the &quot;dynamic&quot; tilting can adjust to current velocity, on-the-fly (in addition to smoothing out transitions). The rail camber&#x2F;cant can remain suited to the typical velocity of non-tilting trains using the same track.