Introduction. The susceptibility of traditional building materials to corrosion has a negative impact on the durability of bridge structures. The solution to the problem of bridge durability is the use of corrosion-resistant fiber-reinforced polymer composites as the main load-bearing elements of superstructures. The joint performance of composites and traditional building materials ensures the most efficient use of the strength potential. The purpose of the study is to unify the design of superstructures, having load-bearing elements made of fiber-reinforced polymer composites by applying a well-known design solution to typical lengths of superstructures to increase the competitiveness of hybrid structures. Materials and methods. Unified parameters of hybrid superstructures are determined. Unification is carried out through the calculation and design of each individual span size. Since the calculation pattern is identical for each structure, the same algorithm, developed by the authors, is employed to make calculations for each span length. The calculation of the roadway slab is performed using the engineering method of “the imprint”. Calculations of fiberglass elements of the main trusses are made using finite element models of hybrid superstructures with account taken of the characteristics of the materials used. Results. Calculations were made and four hybrid superstructures, having main load-bearing elements made of fiberglass, were designed; a well-known unified design pattern was implemented in the designed elements. The main performance indicators of unified superstructures are determined and compared with those of similar structures made of traditional building materials. Conclusions. A unified line of hybrid superstructures, having standard lengths, has been designed. Each has a set of structural drawings, which can be used both at the stage of the trial design of structures and at the stage of the project documentation development. Advantages of composite polymer materials, namely, their applicability in hard-to-reach areas of the country, are demonstrated.