Operational Ranking of Intersections: A Novel Prioritization Methodology

Many road agencies have incorporated network screening for identification of sites with potential for safety improvements as part of their annual safety programs. The Highway Safety Manual includes well established approaches for conducting network screening from safety perspectives. The final result of a road safety network screening is ranked lists of intersections or road sections which require operational or capital improvements. There is a growing interest among road agencies to use a systematic approach to screen their network in order to identify sites which could benefit from operational improvements. The objective of this paper is to develop a methodology for prioritizing signalized and unsignalized intersections to identify those which could potentially benefit from operational improvements. In this paper a two-level prioritization methodology is proposed: a) a high level screening to identify a short-list of intersections, and b) a detailed modeling and analysis exercise to finalize the ranking list. The first level of screening is based on relative traffic volumes on major and minor road approach of intersections. The second level of screening requires detailed lane configurations, traffic signal timing, and turning movement counts. It is also recognized that some of the safety problems at a site are as a result of operational problems. Therefore, the potential for safety improvement values calculated from road safety network screening are incorporated into the proposed methodology. In this paper, the application of the proposed methodology is demonstrated through ranking of 263 signalized intersections and 128 stop-controlled intersections within the Regional Municipality of Halton in Ontario, Canada. Among each category, 30 signalized intersections and 35 stop-controlled intersections are identified as the most in need for operational improvements. The methodology and results of this paper can be used by other municipalities in order to identify intersections which require operational improvements. This process is also beneficial in assisting municipalities in their annual budgeting practices