An Investigation of Selection Criteria for Highway Interchanges

Due to the lack of a strong hierarchy of intersecting roads, and their inability to accommodate common traffic patterns, existing interchange designs can be deficient. When planning for a major reconstruction or a new construction, the design engineer uses a variety of data; such as safety, environmental concerns, projected traffic data, project costs, and right-of-way needs, to select the type and configuration of an interchange that will most efficiently serve the project objectives. That is when a sufficient knowledge of the characteristics of different interchanges can help with the choice that results in the best operational performance with acceptable cost. The purpose of this article is to develop guidelines that a designer can use for the preliminary selection of the optimum interchange type for the project location. This study provides a comparison of functional characteristics of different interchanges, which the designer can use as a starting point for his design.