It's designed for in the road/track, not the vehicle. For train tracks in the UK the recommended max jerk is 0.35 mm/s/s/s. The jerk is limited by using 'Euler

It's designed for in the road/track, not the vehicle. For train tracks in the UK the recommended max jerk is 0.35 mm/s/s/s. The jerk is limited by using 'Euler spiral' sections to join up the straights and the curves. Travelling along an Euler spiral at constant speed means you feel constant jerk laterally, so can be scaled to keep the jerk below any arbitrary value.