Directional midblock median opening with Left-Turn Lanes and Loons between four-leg signalized intersections without median openings have been designed to smooth flow of traffic especially on Main Street. Since 2004, there has been growing interest in their potential benefits as raising mental capacity of drivers due to flow instead of stop by traffic signal. This interest has created a need for data regarding the safety effect of U-Turns. In this dissertation, the effect on u-turns crashes of converting signalized intersection in Tehran from traffic signal removal to install Directional midblock median was estimated. The six such conversions were studied in this research. Safety analysis of u-turns conversions was done by using Before –After study and modeling of U-turns crashes with statistics methods. An Empirical Bayesian (EB) procedure was used to evaluate safety of u-turns conversions. In addition, the history of accidents was studied in both period of before and after treatment.