An approach for auditing highway sections for safety improvements
The objective of this paper is to present a framework for the evaluation of traffic safety improvements on rural highways based on the existing process of the Ministry of Transportation of Ontario (MTO). The framework includes four steps to identify hazardous locations and determine the most feasible improvements. The framework was applied to a 2.2 km segment on Highway 17 (Ontario, Canada) to illustrate how the framework might be implemented in practice. The first step is defining the highway section to be studied. This section is usually a segment that was constructed in the same contract, and its surface conditions require major maintenance. The evaluation of traffic safety on sections that are undergoing major pavement rehabilitation will reduce the overall cost of road maintenance. The second step is to collect and analyze collision data, along with traffic and geometric data. The purpose of this step is to compare the actual number of collisions on the section with the expected long-run mean value and identify the causes of collisions. Based on this analysis, the third step identifies the possible improvements that would eliminate or minimize the number of collisions. These improvements can be as simple as signing improvement or as complex as a major realignment. Finally, these improvements are evaluated economically and environmentally. For this study, several sections of the Ministry of Transportation of Ontario, other ministries and levels of government, and interest groups participated in the evaluation process. A refined MTO process, currently being considered for implementation, is briefly described along with a discussion of its key features.Key words: evaluation, highway improvements, safety, three-dimensional alignments, sight distance, collision frequency.