Investigating Dynamic Ambiguities Screens 30-60

One of the most important challenges in our country is traffic accidents and its related issues. One such analysis was the alleged "60% of suburban crashes within 30 kilometers of cities" followed by actions such as launching a 30-60 screen with the help of various agencies. Given the cost-effectiveness of such actions for society, it is essential that they be based on sound principles. But examining the assumptions and results of this study shows that there are some fundamental ambiguities. These ambiguities can be seen in both the aforementioned dynamic and some of the related research. Therefore, the present study aimed to explain these ambiguities and to study this issue in a qualitative-quantitative way. In this regard, the methods of content analysis and spatial analysis using network analysis technique in Arc GIS 10.2 software have been used. The results show that about 85 percent of the city's outskirts are within 30 kilometers of the city, which is much wider than previously thought, resulting in disproportionate planning and action. This is due to the ambiguity of the scopes involved in defining and applying the concept of the city, resulting in inefficient analyzes.