A roundabout is an intersection in which traffic flows around a central island. Traditional multi-lane roundabouts have many branch lanes without traffic signs, leading to a high tendency for traffic collisions. This paper uses a traffic simulation study by using Vehicle trajectories from the micro-simulation model (VISSIM) software and exporting them to the Substitute Safety Assessment Model (SSAM) to predict traffic conflicts at three sites of four-legged roundabouts in the city of Karbala (Iraq). When the model was calibrated, the mean absolute error of prevention (MAPE) decreased, the fit between the simulated and actual conflicts improved, and Geoffrey E. Haven (GEH) statistic values were less than 5.0 at each exit and entry to the study roundabouts. The study’s traffic safety evaluation includes time-to-collision (TTC) as a traffic conflict indicator. Up to 86% of all crashes were rear-end conflicts, the most common in all locations. The intensity of the disputes has led to the classification of Saeed Al Asar as a medium-risk roundabout, with a TTC of 1.01 s, and Al Mohafada and Al-Tarbia as high-risk roundabouts, with TTC of 0.87 and 0.92 s., respectively.