Transition Curves
A curve should not become a straight all at once, but should gradually increase in radius over time (a distance of around 40 m - 80 m for a line with a maximum speed of about 100 km/h). Even worse than curves with no transition are reverse curves with no intervening straight.
The super-elevation (aka cant) must also be transitioned.
The higher the speed, the longer the transition.
Read more about this topic: Minimum Railway Curve Radius
Famous quotes containing the words transition and/or curves:
“Some of the taverns on this road, which were particularly dirty, were plainly in a transition state from the camp to the house.”
—Henry David Thoreau (1817–1862)
“At the end of every diet, the path curves back toward the trough.”
—Mason Cooley (b. 1927)