For maintenance of existing bridges, it is very important to identify the current state of bridge. In order to evaluate load rating of a bridge, real behavior characteristics of bridge obtained by analyzing the measured data and static/dynamic responses calculated through numerical analysis are needed. However, evaluating current state and/or load rating of bridge is not easy, because there are many difficulties in measuring bridge behaviors and making accurate FE model. The Korea Expressway Corporation has developed the ‘Smart Load Rating Method’ for bridge which is able to evaluate the current state of bridge with dynamic properties and has been applying in Highway bridges. In this study, we have successfully fulfilled analyzing dynamic properties and evaluating the state of an old steel gerber bridge in Texas USA by using the Smart Load Rating method