curve-curve intersection
transition curve；easement curve；spiral transition curve
approach to curve by curve
continuous cooling transformation curve CCT curve
C-V curve (capacitance-voltage curve)
operating characteristic curve OC curve
time-distance curve (=travel-time curve)
travel-time curve (=time-distance curve)
uniformly tangent non-uniform corner cutting curve (UNC curve)
‘ 1: 1: 1’ design method for transition curve
2-D speed protection curve