This paper discusses the development of a set of application heuristics intended to provide guidance for designers faced with the challenge of developing end-of-freeway transition zones from a freeway environment to a signalized intersection. The work was carried out for the Ontario Ministry ofTransportation to help develop specific guidance for a specific roadway in eastern Ontario, but the overall objective of the work was also to guidethe design of future transitions. The foundation of the work is observational and based on a review of six freeway transition sections in Ontario. A multiple-lines-of-evidence approach was used that began with a review ofthe physical and operational elements present at each site from a distance of 2 to 3 km upstream of the end of freeway to beyond the first signalized intersection. This was used to help identify risk elements that were present on these transitions. Speed profiles were collected at several standard points throughout the transition section as well as on the freeway prior to the beginning of the transition. These profiles were used to help examine the likely effects of the transition characteristics on driver speedchoice. Collision histories along the various transitions were also examined including a limited but revealing Empirical Bayes analysis on the terminal intersections themselves. In the concluding section of the paper, the authors summarize the findings of the various investigations and develop a generalized set of application heuristics for the design of freeway transitions to signalized intersections.
Abstract