The object of research is a drainage bridge tray made of glass fiber-reinforced polymer. This work aims to study the physical and mechanical characteristics of glass fiber-reinforced polymer used to produce drainage bridge trays and determine the operational characteristics of a typical suspended drainage tray. Method. Experimental studies are carried out to determine the physical and mechanical characteristics of fiberglass: density, water absorption, Barcol's hardness, compressive strength, tensile strength, compressive modulus of elasticity, and tensile modulus of elasticity. The operational properties of a typical suspended drainage tray are determined using hydraulic calculations. Results. The physical and mechanical characteristics of glass fiber-reinforced polymer are suitable when exposed to aggressive environments in difficult climatic conditions, including producing drainage structures for bridge roadways. The density of the glass fiber reinforced polymer is 1770 kg/m3; water absorption is 0.42%, Barcol's hardness is 41 units, compressive strength in the direction 0°/90° is 108.3 MPa/100.4 MPa, tensile strength in the direction 0°/90° is 165.8 MPa/150.1 MPa, modulus of elasticity in compression in the direction 0°/90° is 11.7 GPa/9.7 GPa, modulus of elasticity in tension in the direction 0°/90° is 13.9 GPa/10.0 GPa. The proposed design solution for a drainage bridge tray made of glass fiber reinforced polymer ensures the passage of the calculated flow rate of rainwater runoff 125.71 l/s when filled, not exceeding the maximum allowable.