Section loss is a general term associated with reduction in the cross-sectional area of a member due to extreme loading, repeated load cycles, rebar carbonation, etc. To ascertain this magnitude of loss, this study strived to understand the parameters involved. In reinforced concrete (RC) members, section loss may begin with the steel and then the effect spilled over to the concrete or vice versa which then gets affected by atmospheric influents. In any case, technically the section (T-girder, rectangular section, etc.) is reduced or compromised, thus reducing its capacity and leading to an irreversible path to structural inefficiency. A building-block deficiency, crack from either extreme or repeated loading is a major contributor to section loss. Cracks were then thoroughly analyzed and a crosscheck was then authenticated against similar research (i.e., virtual laboratory) and finally LISA FEA was used to model and simulate the cracked design to monitor the response of the section in term of capability and performance. This research then derived and presented a direct relationship between flexural crack width and deflection. The proposed equation is in good agreement with the output of the finite element software.rnTraditionally made of reinforcing bars and concrete, RC members have over the years been studied to investigate the particulate nature of the constituent elements acting as a unit. The analysis and design of cast-in-place railway bridges, like many other railway bridges, incorporates the application of several load types that are usually of very high magnitudes. The combination of these loads depicts the large depth-to-width ratios of flexural members. These loads include: dead load, live load, impact, Centrifugal force, Earth pressure, Buoyancy, Wind Load on Structure, Wind load on Live Load, Longitudinal force from Live Load, Longitudinal force due to Friction, or Shear Resistance at Expansion Bearing, Seismic, Stream Flow Pressure, Ice Pressure, Temperature, Rib Shortening, Shrinkage, Settlement of supports etc. Here, a railway superstructure is analyzed, and the load-carrying flexural member is designed. This research focused on the engineering that leads to cracks and the performance of the member considered. Cracks are one of the building blocks of long-term deformation in a structural member. This research employed several analytically comparative methods that investigated the trends and magnitude of section loss on the girder of a cast-in-place railway bridge by completely analyzing the girder manually under several static and dynamic loading conditions utilizing different materials strength parameters. The analysis informed the research about key characteristics of the girder to include: girder depth, girder width, and area of steel. These structural parameters were then used against a symbolic beam that were tested in the laboratory. Results from a virtual laboratory, to include crack dimensions, stiffness, were then used in the model of the cracked girder to understand the mode of response of the girder of these cracks.rnUsing the LISA FEA 8.0.0, approximate representations of crack widths were simulated into the model using the same material strength parameters as contained in the manual computational analysis. The performance of the girder was then rated based on allowable capacities as given in several references, regulatory materials, codes, and standards. It was observed and noted that up to the design crack width, the cracked section deflected steadily, and that the deflected cracked section is as twice as the uncracked section.