Samenvatting
An extensive historical review is made of the development of design policies for the horizontal alignment of road curves, and the concepts underlying them. Particular aspects considered are: (1) the assumption made about vehicle speeds; (2) the criteria for determining "safe speeds" on highway and intersection curves; (3) the superelevation associated with different degrees of curvature; and (4) the criteria for effecting transitions in curvature, superelevation and pavement width.