In this study, the impact loading test was carried out at the highway bridge. By comparing with static loading test results, the application to the degradation degree evaluation of the bridge slab was investigated. As a result, deterioration was not observed in this slab in any method. In application to degradation degree evaluation, it became clear that it is important to consider the difference from the static action taking into consideration that the impact test is a dynamic action. Also, when assessing the degree of deterioration with curvature, it was shown that care should be taken in evaluating the Young's modulus value in a relatively healthy bridge slab.