Abstract
A movable concrete safety- shape barrier has been proposed for use in reversible- lane configuration on the Tappan Zee Bridge of the New York State Thruway. Previous tests indicate that this barrier provides performance comparable to standard rigid- concrete safety- shape barrier, except for deflecting laterally on impact. This report concerns a model developed to assess the risk of interference collisions. Traffic and geometric conditions on the structure and the barrier s deflection characteristics were used to calculate the probability that a primary impact on the barrier would result in interference with opposing traffic.