This document reviews different types of crash barriers used in roadways and their safety performance evaluations. It discusses various studies that have evaluated crash barriers through computer simulations, crash tests, and analyses of real-world collision data. The key findings are that different barrier designs have varying safety advantages, with weaker barriers generally performing better in reducing occupant injuries. Finite element modeling is commonly used to simulate impacts before physical crash testing. Evaluation criteria include structural integrity, risk to occupants, and vehicle trajectory after collisions. The document concludes that crash barriers effectively reduce the severity of accidents but may increase total collision numbers by redirecting vehicles rather than allowing them to leave the roadway.