Bridges play a vital role in modern transportation infrastructure and are essential components of road networks. With the continuous increase in traffic volume, bridges are subjected to repeated loading, which can lead to structural deterioration over time. Therefore, understanding the interaction between vehicles and bridge structures is crucial for ensuring their safety, durability, and serviceability. The primary objective of bridge engineering is to efficiently utilize structural materials and design methods to achieve optimal performance and economy.

This study presents the analysis and design of a steel I-girder bridge and introduces a comprehensive design methodology developed during the research. The work focuses on evaluating the current design practices and comparing the provisions outlined in the Indian Roads Congress (IRC) specifications with those of the American Association of State Highway and Transportation Officials (AASHTO). The comparative assessment highlights the similarities and differences between the two design standards for steel I-girder bridges.

The bridge model was developed and analyzed using CSI Bridge software, which provides a parametric, object-based modeling environment for bridge engineering applications. The software enables efficient creation of analytical bridge models while integrating material properties, geometric configurations, loading conditions, and design parameters within a unified framework. This object-oriented approach simplifies the modeling process and enhances the accuracy and efficiency of bridge analysis and design.

 Keywords: Steel I-Girder Bridge, Structural Analysis, Bridge Design, CSI Bridge Software, IRC Specifications, AASHTO Standards, Parametric Modeling.