For a long time, controlling the speed of vehicles, or in other words, controlling the behavior of drivers in adopting speed, has been and is one of the most important challenges for road safety engineering. In this regard, there are various tools for controlling the speed of vehicles on the roads,the most important tool used all over the world is the use of speed limit signs. To determine the speed limit when constructing roads, there is a common trend that the relevant authorities are more or less familiar with. However, determining the appropriate speed limit on existing roads after several years of operation requires speed Scrutinize studies, that the country's road engineering community is not well known. The goal of speed Scrutinize studies on an axis is to obtain the speed limit for vehicles. In order to acquaint the engineering community of the country with this issue, in this research, the speed Scrutinize study has been used to determine the speed limit on the Semirom-Yasuj axis. The present study is based on the study of speed-based research in 2016. The method used is that after the traffic studies and the available data, the study axis is based on the aerial maps of the initial segmentation and after the field visit, the final segmentation is obtained. Speed information is also measured in two ways: point speed and garlic speed. Finally, the information is analyzed and the speed limit of each part is determined.