Road Surface Development and Sight Distance Calculation with New Visualization Methods

The recent advances in computer visualization methods have made it possible to exploit the possibility of applying scientific visualization methods in critical research areas in the field of transportation engineering. In this paper we develop new visualization methods for road design and safety. Typically, roads are designed by combining horizontal and vertical roadway alignments, to allow for adequate sight distance for driver comfort and safety. The traditional process of checking for adequate sight distance ahead of a driver is manual as it is performed by a manual check along the horizontal and vertical roadway alignments. Further, recent visualization applications in horizontal and vertical alignment design is a sequential process (i.e., visualization of horizontal and vertical alignments is carried out in separate stages; typically horizontal alignment is obtained first and a vertical alignment is subsequently fitted, which may lead to inaccurate sight distances along the roadway. For example, a section of a road with a vertical hog curve and a sharp horizontal curve together will lead to an illusion of the availability of a larger sight distance when driving. In this paper, a new visualization-based method for calculating the sight distance is proposed in which the sight distance is measured using a 3-dimensional (3D) road surface, solid cone, rectangular plane. The 3D cone with its vertex at a height ‘h’ from the road surface and line of height parallel to the tangent of the road centreline is moved along the roadway at regular intervals. The intersection of the road surface with the cone is used to obtain the intersected surface. The variation of the tangents along the intersected surface is used to obtain the profile of the intersected road surface centreline. Variable rectangular plane is used over the intersected road surface to get the sight distance. Given the 3D road centreline, a method is described to establish the road surface Mathematical formulations to calculate the 3D surface and sight distance are presented. The paper concludes with the discussion of the application of the proposed methods for full-scale efficient roadway sight distance measurement as well as directions for future research. Key-Words: Visualization in Physical Sciences, Life Sciences and Engineering; Virtual Environments, Virtual Reality, Highway Design, Sight Distance