The object of the research is the structures of spans made of two types of steel of different strengths. The article examines the effectiveness of the use of the bisteel beams of bridge structures based on a technical and economic analysis, which consists of determining the value of construction and structural coefficients for beams of the same spans in order to identify metal savings. In the course of the study, the effectiveness of using steels of various strengths in a set was confirmed. The material described in the article can be used as the basis for the practical application of bisteel spans.