Studies of the second lane of the Yasuj-Semirom route, between Patavah and Qara Bridge, with a length of 33 km, have been carried out by Sepahan Jame Kar Consulting Engineers. These studies have been carried out with the aim of improving the safety as well as the geometric and traffic characteristics of the existing route. This route is of great importance due to its location in the south-north connecting corridor (the cities of Bushehr and Yasuj to Isfahan and Shahrekord), which has also made it a transit route.