Evaluation of selection factors underpass and overpasses at intersections (Case study: the intersection of Kharazi Highway with Shahid Bagheri,Zone 22 in Tehran, Iran)

Grade-separated junctions (grade separations) play a significant role in increasing the utility of traffic parameters in urban transportation network and they are considered as the most important transportation infrastructure in all paths especially in urban streets. Once the conditions for the construction of a grade-separated- junction is met and the economic justification is provided, one should choose one of a variety of grade separations including overpasses or underpasses. This research evaluates the factors influencing the selection of underpasses and overpasses at intersections (Case study: Shahid Kharrazi Highway junction with 45m Shahid Bagheri and Arghavan Blvd). This study is applied in terms of purpose, survey in terms of data collection and quantitative based on the nature of data. The statistical population of the study consisted of technical and professional people in traffic such as transportation and traffic engineers in Tehran's 5th and 22nd district municipalities who were selected randomly. In this research, the required data was collected using a researcher-made 13-item questionnaire. To examine and test variables, hierarchical regression was used with SPSS software. Regarding the results of the regression equations, the variables are classified into three categories in importance. Accordingly, if , the grade separation is an underpass, if , the grade separation is an overpass and the type of grade separation for is determined based on the experts of the civil and transportation sector.