Sound Barriers Site selection in Karaj Major Routes Using TOPSIS

Nowadays site selection of an appropriate location for a project can be one of the most important success factors. This research was done in order to find suitable locations for sound barriers in Karaj. In this research, after a literature review and gathering the expert opinions, the criteria and sub-criteria were determined. Then, the standardized criteria and sub-criteria maps were prepared by fuzzy standardization method. To obtain weights of criteria and sub-criteria, the pairwise comparison were used. Then, the suitability map for the implementation of sound barriers were obtained with weighted linear combination (WLC). Next, by field visit and measuring the sound level and examining the possibility of barrier installation, nine routes were selected from the suitability map. In the next step, using the TOPSIS method, priority 9 selected routes were done. The results of this study indicated that the most important criteria for locating sound barriers were urban routes (passages, thoroughfare), equivalent sound level (Leq), urban traffic, land use, population density, sensitive locations to noise, distance to passages, topography (slope), height of buildings, and vegetation respectively. The sound level measuring results showed the most polluted routes were the route 2 (M2), located in the second district of Karaj municipality, route 1 (M1) in the eleventh region and route 5 (M5) in the fifth region respectively. The TOPSIS results showed the appropriate routes were to install the sound barriers were route 9 (located at Golshahr Boulevard) and route 7 (Shahid Rajaee Boulevard – Zafar) and route 6 (Allameh Jafari Boulevard, Islamic Republic of Iran – Aras), and route 2 (Freeway Karaj-Qazvin, Fardis bridge to Golshahr), respectively. The results of this research can be applied to implement the sound barriers by Karaj municipal and this approach can be used in other cities.