This paper was presented at the session titled `Risk management in the roads sector - geometric design'. The functional design of highways is a process that relies on both quantitative data, such as capital and maintenance costs, as well as more qualitative data, such as safety and road user costs. While the former considerations are usually relatively well-defined by the physical characteristics of the project, the latter inputs to the functional design process are often the subject of much debate and research among highway professionals. This paper details the results of a research project aimed at better defining the more subjective effects of a specific aspect of roadway improvements, namely those which eliminate or reduce transitions in horizontal alignment. The objective of this research project is to provide recommendations for improving Saskatchewan Highways and Transportation's ability to incorporate the effects of horizontal curves on the motoring public into its assessment of the benefits and costs associated with a given project or route. While these implications include travel time delays and vehicle operating costs, the most significant factor to be defined is the effects of horizontal curves on traffic safety. This project was, thus, expressly designed in order to improve the effectiveness of the analysis of the benefits and costs associated with various routings and alignments of rural highways in Saskatchewan. (A)
Abstract