Use of Computer Animation in Quantifying Driver Perception of Three-Dimensional Road Alignments

摘要

Previous studies have shown that the current practice of highway geometric design, which is based on two-dimensional (2D) analyses, is a primary source of inaccurate driver's perception. Design guidelines, therefore, recommend designer to examine and adjust the alignment during the different design stages based on its three-dimensional (3D) visual quality. Tools that can be used in such a task include continuous roll of plan-profile papers, perspective drawings, and computer software. However, an established procedure with clearer and more quantitative guidelines would undoubtedly ensure less subjectivity and greater uniformity in alignment design. Such a procedure would require the quantification of several items pertaining to driver perception and behavior. This paper presents a summary of three different experiments carried out by the authors where computer animations were used to examine and quantify concerns related to driver perception. The objective of the first experiment was to determine the distance required by drivers to perceive the existence of a horizontal curve, which may be restricted by an existing crest vertical curve. The second experiment was designed to examine the hypothesis that horizontal curves appear sharper or flatter when overlapping with crest or sag vertical curves, respectively. Finally, the objective of the third experiment was to quantify the relationship between the actual and perceived radii. While all experiments utilized computer simulation of the road alignment, each experiment was designed differently to address its respective objective.