Research was conducted to study some particular ways in which the highway designer can be assisted in his task of designing a visually stimulating highway. The research was limited to the following: (1) the sag vertical curve was studied in order to place limits on the lenght of vertical curve so that an aesthetically pleasing ribbon of roadway will result, and (2) a small change in direction of horizontal alignment was studied to determine the length of curve required for the alignment to appear smooth and flowing rather than a kink. Computer-drawn perspectives of the roadway from the driver's vantage point were made and provided a highly realistic picture. A large number of perspective drawings provided the basis for a graph showing visually desirable and acceptable relationships between the length of sag vertical curve and viewing distances for various grade changes. This graph should be of significant aid to the highway designer. In a similar manner perspective drawings of the kink alignment provided the basis for a number of conclusions regarding the appearance of the alignment with respect to various locations of the observer and various lengths of horizontal curve. A previously unpublished technique, developed by others, transforming space coordinates to picture plane coordinates (perspective drawing coordinates) is included. Perspective drawings, produced by the electronic plotter, provided a highly versatile and valuable tool and show great promise as an aid to the highway designer in his complex task
Abstract